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Macrophage responses to activation are fluid and dynamic in their ability to respond appropriately to challenges, a role integral to host defence. While bacteria can influence macrophage differentiation and polarization into pro-inflammatory and alternatively activated phenotypes through direct interactions, many questions surround indirect communication mechanisms mediated through secretomes derived from gut bacteria, such as lactobacilli. We examined effects of secretome-mediated conditioning on THP-1 human monocytes, focusing on the ability of the Lacticaseibacillus rhamnosus R0011 secretome (LrS) to drive macrophage differentiation and polarization and prime immune responses to subsequent challenge with lipopolysaccharide (LPS). Genome-wide transcriptional profiling revealed increased M2-associated gene transcription in response to LrS conditioning in THP-1 cells. Cytokine and chemokine profiling confirmed these results, indicating increased M2-associated chemokine and cytokine production (IL-1Ra, IL-10). These cells had increased cell-surface marker expression of CD11b, CD86, and CX 3 CR1, coupled with reduced expression of the M1 macrophage-associated marker CD64. Mitochondrial substrate utilization assays indicated diminished reliance on glycolytic substrates, coupled with increased utilization of citric acid cycle intermediates, characteristics of functional M2 activity. LPS challenge of LrS-conditioned THP-1s revealed heightened responsiveness, indicative of innate immune priming. Resting stage THP-1 macrophages co-conditioned with LrS and retinoic acid also displayed an immunoregulatory phenotype with expression of CD83, CD11c and CD103 and production of regulatory cytokines. Secretome-mediated conditioning of macrophages into an immunoregulatory phenotype is an uncharacterized and potentially important route through which lactic acid bacteria and the gut microbiota may train and shape innate immunity at the gut-mucosal interface., (© 2024. His Majesty the King in Right of Canada as represented by the Minister of Agriculture and Agri-Food Canada, and The Author(s) 2024.)

Scope: Gastro-AD (GAD) is a soy flour derived product that undergoes an industrial fermentation with Lactobacillus delbrueckii R0187 and has demonstrated clinical effects in gastroesophageal reflux and peptic ulcer symptom resolution. The aim of this study is to describe and link GAD's metabolomic profile to plausible mechanisms that manifest and explain the documented clinical outcomes., Methods and Results: 1 H NMR spectroscopy with multivariate statistical analysis is used to characterize the prefermented soy flour and GAD products. The acquired spectra are screened using various resources and the molecular assignments are confirmed using total correlation spectroscopy (TOCSY). Peaks corresponding to different metabolites are integrated and compared between the two products for relative changes. HPLC and GC are used to quantify some specific molecules. NMR analyses demonstrate significant changes in the composition of various assigned bioactive moieties. HPLC and GC analysis demonstrate deglycation of isoflavones after fermentation, resulting in estrogenically active secondary metabolites that have been previously shown to help to reduce inflammation., Conclusion: The identification of bioactive molecules, such as genistein and SCFAs, capable of modulating anti-inflammatory signaling cascades in the stomach's gastric and neuroendocrine tissues can explain the reported biological effects in GAD and is supported by in vivo data., (© 2024 Lallemand Inc. Molecular Nutrition & Food Research published by Wiley‐VCH GmbH.)

Background: Healthy individuals may experience increases in intestinal permeability after chronic or acute use of non-steroidal anti-inflammatory drugs, which may be attenuated by probiotics. This study investigates the effects of an acute aspirin challenge on gastroduodenal barrier function with or without prophylactic probiotic consumption., Methods: Twenty-nine generally healthy participants (26 ± 6 years) completed a 14-week randomized, double-blind, crossover trial. A probiotic containing 2 Lactobacilli strains or placebo was administered for 3 weeks, with a 4-week washout period between crossover phases. Daily and weekly questionnaires assessing gastrointestinal function were completed for 2 weeks before until 2 weeks after each intervention to assess gastrointestinal function. Gastroduodenal permeability was assessed by urinary excretion of orally administered sucrose after 1, 2, and 3 weeks of each intervention with a 1950 mg-aspirin challenge after 2 weeks of supplementation. Stool samples were collected weekly during supplementation for detection of species of interest., Results: Gastroduodenal permeability increased with aspirin challenge (Week 1: 3.4 ± 0.6 μmol vs Week 2: 9.9 ± 1.0 μmol urinary sucrose; p < 0.05). There were no differences in the change in permeability after the aspirin challenge or gastrointestinal function between interventions., Conclusion: The acute aspirin challenge significantly increased intestinal permeability similarly in both groups, and prophylactic probiotic consumption was unable to prevent the loss in this particular model., (© 2023. The Author(s).)

Background: Recent advances linking gut dysbiosis with neurocognitive disorders such as Alzheimer's disease (AD) suggest that the microbiota-gut-brain axis could be targeted for AD prevention, management, or treatment., Objective: We sought to identify probiotics that can delay Aβ-induced paralysis., Methods: Using C. elegans expressing human amyloid-β (Aβ)1-42 in body wall muscles (GMC101), we assessed the effects of several probiotic strains on paralysis., Results: We found that Lacticaseibacillus rhamnosus HA-114 and Bacillus subtilis R0179, but not their supernatants or heat-treated forms, delayed paralysis and prolonged lifespan without affecting the levels of amyloid-β aggregates. To uncover the mechanism involved, we explored the role of two known pathways involved in neurogenerative diseases, namely mitophagy, via deletion of the mitophagy factor PINK-1, and fatty acid desaturation, via deletion of the Δ9 desaturase FAT-5. Pink-1 deletion in GMC101 worms did not modify the life-prolonging and anti-paralysis effects of HA-114 but reduced the protective effect of R0179 against paralysis without affecting its life-prolonging effect. Upon fat5 deletion in GMC101 worms, the monounsaturated C14:1 and C16:1 FAs conserved their beneficial effect while the saturated C14:0 and C16:0 FAs did not. The beneficial effects of R0179 on both lifespan and paralysis remained unaffected by fat-5 deletion, while the beneficial effect of HA-114 on paralysis and lifespan was significantly reduced., Conclusions: Collectively with clinical and preclinical evidence in other models, our results suggest that HA-114 or R0179 could be studied as potential therapeutical adjuncts in neurodegenerative diseases such as AD.

Background: An emerging strategy to treat symptoms of gastrointestinal (GI) dysmotility utilizes the administration of isolated bacteria. However, the underlying mechanisms of action of these bacterial agents are not well established. Here, we elucidate a novel approach to promote intestinal motility by exploiting the biochemical capability of specific bacteria to produce the serotonin (5-HT) precursor, tryptophan (Trp)., Methods: Mice were treated daily for 1 week by oral gavage of Bacillus (B.) subtilis (R0179), heat-inactivated R0179, or a tryptophan synthase-null strain of B. subtilis (1A2). Tissue levels of Trp, 5-HT, and 5-hydroxyindoleacetic acid (5-HIAA) were measured and changes in motility were evaluated., Key Results: Mice treated with B. subtilis R0179 exhibited greater colonic tissue levels of Trp and the 5-HT breakdown product, 5-HIAA, compared to vehicle-treated mice. Furthermore, B. subtilis treatment accelerated colonic motility in both healthy mice as well as in a mouse model of constipation. These effects were not observed with heat-inactivated R0179 or the live 1A2 strain that does not express tryptophan synthase. Lastly, we found that the prokinetic effects of B. subtilis R0179 were blocked by coadministration of a 5-HT 4 receptor (5-HT 4 R) antagonist and were absent in 5-HT 4 R knockout mice., Conclusions and Inferences: Taken together, these data demonstrate that intestinal motility can be augmented by treatment with bacteria that synthesize Trp, possibly through increased 5-HT signaling and/or actions of Trp metabolites, and involvement of the 5-HT 4 R. Our findings provide mechanistic insight into a transient and predictable bacterial strategy to promote GI motility., (© 2023 The Authors. Neurogastroenterology & Motility published by John Wiley & Sons Ltd.)

The interplay between the intestinal microbiota and host is critical to intestinal ontogeny and homeostasis. MicroRNAs (miRNAs) may be an underlying link. Intestinal miRNAs are microbiota-dependent and, when shed in the lumen, affect resident microorganisms. Yet, longitudinal relationships between intestinal tissue miRNAs, luminal miRNAs, and luminal microorganisms have not been elucidated, especially in early life. Here, we investigated the postnatal cecal miRNA and microbiota populations, their relationship, and their impact on intestinal maturation in specific pathogen-free mice; we also assessed if they can be modified by intervention with allochthonous probiotic lactobacilli. We report that cecal and cecal content miRNA and microbiota signatures are temporally regulated, correlated, and modifiable by probiotics with implications for intestinal maturation. These findings help understand causal relationships within the gut ecosystem and provide a basis for preventing and managing their alterations in diseases throughout life. IMPORTANCE The gut microbiota affects intestinal microRNA (miRNA) signatures and is modified by host-derived luminal miRNA. This suggests the existence of close miRNA-microbiota relationships that are critical to intestinal homeostasis. However, an integrative analysis of these relationships and their evolution during intestinal postnatal maturation is lacking. We provide a system-level longitudinal analysis of miRNA-microbiota networks in the intestine of mice at the weaning transition, including tissue and luminal miRNA and luminal microbiota. To address causality and move toward translational applications, we used allochthonous probiotic lactobacilli to modify these longitudinal relationships and showed that they are critical for intestinal maturation in early life. These findings contribute to understand mechanisms that underlie the maturation of the intestinal ecosystem and suggest that interventions aiming at maintaining, or restoring, homeostasis cannot prescind from considering relationships among its components., Competing Interests: E.M.C. has received research support from the Lallemand Health Solutions and Ocean Spray and has received consultant fees from Danone. All other authors declare no conflict of interests. The probiotic strains utilized in this study were provided by the Lallemand Health Solutions (LHS), Inc.

We have shown previously that the ketogenic diet (KD) is effective in reducing seizures associated with infantile spasms syndrome (ISS) and that this benefit is related to alterations in the gut microbiota. However, it remains unclear whether the efficacy of the KD persists after switching to a normal diet. Employing a neonatal rat model of ISS, we tested the hypothesis that the impact of the KD would diminish when switched to a normal diet. Following epilepsy induction, neonatal rats were divided into two groups: continuous KD for 6 days; and a group fed with KD for 3 days and then a normal diet for 3 days. Spasms frequency, mitochondrial bioenergetics in the hippocampus, and fecal microbiota were evaluated as major readouts. We found that the anti-epileptic effect of the KD was reversible, as evidenced by the increased spasms frequency in rats that were switched from the KD to a normal diet. The spasms frequency was correlated inversely with mitochondrial bioenergetic function and a set of gut microbes, including Streptococcus thermophilus and Streptococcus azizii. These findings suggest that the anti-epileptic and metabolic benefits of the KD decline rapidly in concert with gut microbial alterations in the ISS model., (© 2023 The Authors. Epilepsia published by Wiley Periodicals LLC on behalf of International League Against Epilepsy.)

Ischemic stroke is a debilitating neurological disease with few effective therapeutics. Previous work has shown that oral probiotic treatment prior to stroke can attenuate cerebral infarction and neuroinflammation, highlighting the gut-microbiota-brain axis as a novel therapeutic target. Whether a more clinically relevant, post-stroke, administration of probiotics can improve stroke outcomes is unknown. In this study, we examined the effect of post-stroke oral probiotic therapy on motor behavior in the pre-clinical mouse endothelin-1 (ET-1) model of sensorimotor stroke. We found that post-stroke oral probiotic therapy with Cerebiome ® (Lallemand, Montreal, Canada), containing B. longum R0175 and L. helveticus R0052, improved functional recovery and changed the composition of the post-stroke gut microbiota. Interestingly, oral Cerebiome ® administration did not result in alterations of lesion volume or the number of CD8+/Iba1+ cells in the injured tissue. Overall, these findings suggest that probiotic treatment following injury can improve sensorimotor function., (© 2023. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

Mitochondrial impairment is a hallmark feature of neurodegenerative disorders, such as Parkinson disease, and PRKN/parkin-mediated mitophagy serves to remove unhealthy mitochondria from cells. Notably, probiotics are used to alleviate several symptoms of Parkinson disease including impaired locomotion and neurodegeneration in preclinical studies and constipation in clinical trials. There is some evidence to suggest that probiotics can modulate mitochondrial quality control pathways. In this study, we screened 49 probiotic strains and tested distinct stages of mitophagy to determine whether probiotic treatment could upregulate mitophagy in cells undergoing mitochondrial stress. We found two probiotics, Saccharomyces boulardii and Lactococcus lactis , that upregulated mitochondrial PRKN recruitment, phospho-ubiquitination, and MFN degradation in our cellular assays. Administration of these strains to Drosophila that were exposed to paraquat, a mitochondrial toxin, resulted in improved longevity and motor function. Further, we directly observed increased lysosomal degradation of dysfunctional mitochondria in the treated Drosophila brains. These effects were replicated in vitro and in vivo with supra-physiological concentrations of exogenous soluble factors that are released by probiotics in cultures grown under laboratory conditions. We identified methyl-isoquinoline-6-carboxylate as one candidate molecule, which upregulates mitochondrial PRKN recruitment, phospho-ubiquitination, MFN degradation, and lysosomal degradation of damaged mitochondria. Addition of methyl-isoquinoline-6-carboxylate to the fly food restored motor function to paraquat-treated Drosophila . These data suggest a novel mechanism that is facilitated by probiotics to stimulate mitophagy through a PRKN-dependent pathway, which could explain the potential therapeutic benefit of probiotic administration to patients with Parkinson disease.

Background: Gut microbiota has emerged as a modifiable factor influencing obesity and metabolic diseases. Interventions targeting this microbial community could attenuate biological and psychological comorbidities of excess weight. Objective: Our aim was to determine if Lacticaseibacillus rhamnosus HA-114 supplementation accentuated beneficial impact of weight loss on metabolic and cognitive health. Methods: This 12-week randomized, double-blind, placebo-controlled trial assessed biological markers of energy metabolism, eating behaviors and mood-related factors in 152 adults with overweight receiving L. rhamnosus HA-114 supplementation or placebo, that were also on a dietary intervention inducing a controlled weight loss. Results: Although probiotic supplementation did not potentiate the reduction in body weight or fat mass, a significant decrease in plasma insulin, HOMA-IR, LDL-cholesterol and triglycerides was observed in the probiotic-supplemented group only. With respect to eating behaviors and mood-related factors, beneficial effects were either observed only in the group receiving probiotic supplementation or were significantly greater in this group, including decrease in binge eating tendencies, disinhibition and food-cravings. Conclusion: This study demonstrates the clinical relevance of probiotic supplementation to induce beneficial metabolic and psychological outcomes in individuals with overweight undergoing weight loss. Trial registration: ClinicalTrials.gov identifier: NCT02962583.

Background/aims: Motility, stool characteristics, and microbiota composition are expected to modulate probiotics' passage through the gut but their effects on persistence after intake cessation remain uncharacterized. This pilot, open-label study aims at characterizing probiotic fecal detection parameters (onset, persistence, and duration) and their relationship with whole gut transit time (WGTT). Correlations with fecal microbiota composition are also explored., Methods: Thirty healthy adults (30.4 ± 13.3 years) received a probiotic (30 × 10 9 CFU/capsule/day, 2 weeks; containing Lactobacillus helveticus R0052, Lacticaseibacillus paracasei HA-108, Bifidobacterium breve HA-129, Bifidobacterium longum R0175, and Streptococcus thermophilus HA-110). Probiotic intake was flanked by 4-week washout periods, with 18 stool collections throughout the study. WGTT was measured using 80% recovery of radio-opaque markers., Results: Tested strains were detected in feces ~1-2 days after first intake and persistence after intake cessation was not significantly different for R0052, HA-108, and HA-129 (~3-6 days). We identified 3 WGTT subgroups within this population (named Fast, Intermediate, and Slow), which could be classified by machine learning with high accuracy based on differentially abundant taxa. On average, R0175 persisted significantly longer in the intermediate WGTT subgroup (~8.5 days), which was mainly due to 6 of the 13 Intermediate participants for whom R0175 persisted ≥ 15 days. Machine learning classified these 13 participants according to their WGTT cluster (≥ 15 days or < 5 days) with high accuracy, highlighting differentially abundant taxa potentially associated with R0175 persistence., Conclusion: These results support the notion that host-specific parameters such as WGTT and microbiota composition should be considered when designing studies involving probiotics, especially for the optimization of washout duration in crossover studies but also for the definition of enrollment criteria or supplementation regimen in specific populations.

Growing evidence indicates that non-antibiotic therapeutics significantly impact human health by modulating gut microbiome composition and metabolism. In this study, we investigated the impact of two psychotropic drugs, aripiprazole and (S)-citalopram, on gut microbiome composition and its metabolic activity, as well as the potential of probiotics to attenuate related dysbiosis using an ex vivo model of the human colon. After 48 h of fermentation, the two psychotropics demonstrated distinct modulatory effects on the gut microbiome. Aripiprazole, at the phylum level, significantly decreased the relative abundances of Firmicutes and Actinobacteria, while increasing the proportion of Proteobacteria. Moreover, the families Lachnospiraceae , Lactobacillaceae, and Erysipelotrichaceae were also reduced by aripiprazole treatment compared to the control group. In addition, aripiprazole lowered the levels of butyrate, propionate, and acetate, as measured by gas chromatography (GC). On the other hand, (S)-citalopram increased the alpha diversity of microbial taxa, with no differences observed between groups at the family and genus level. Furthermore, a probiotic combination of Lacticaseibacillus rhamnosus HA-114 and Bifidobacterium longum R0175 alleviated gut microbiome alterations and increased the production of short-chain fatty acids to a similar level as the control. These findings provide compelling evidence that psychotropics modulate the composition and function of the gut microbiome, while the probiotic can mitigate related dysbiosis.

Microbiota studies have dramatically increased over these last two decades, and the repertoire of microorganisms with potential health benefits has been considerably enlarged. The development of next generation probiotics from new bacterial candidates is a long-term strategy that may be more efficient and rapid with discriminative in vitro tests. Streptococcus strains have received attention regarding their antimicrobial potential against pathogens of the upper and, more recently, the lower respiratory tracts. Pathogenic bacterial strains, such as non-typable Haemophilus influenzae ( NTHi ), Pseudomonas aeruginosa ( P. aeruginosa ) and Staphylococcus aureus ( S. aureus ), are commonly associated with acute and chronic respiratory diseases, and it could be interesting to fight against pathogens with probiotics. In this study, we show that a Streptococcus mitis ( S. mitis ) EM-371 strain, isolated from the buccal cavity of a human newborn and previously selected for promising anti-inflammatory effects, displayed in vitro antimicrobial activity against NTHi , P. aeruginosa or S. aureus . However, the anti-pathogenic in vitro activity was not sufficient to predict an efficient protective effect in a preclinical model. Two weeks of treatment with S. mitis EM-371 did not protect against, and even exacerbated, NTHi lung infection.

Increasing evidence suggests that the intestinal microbiota composition could play a role in specific pathologies such as hypertension, obesity and diabetes. This study aims to demonstrate that the intestinal microbiota modulated by a diet creating dysbiosis increased the size of the myocardial infarction and that probiotics could attenuate this effect. To do this, microbiota transplants from rats fed a dysbiotic or non-dysbiotic diet in the presence or absence of probiotics were performed for 10 days on rats whose microbiota had been previously suppressed by antibiotic therapy. Then, the anterior coronary artery of the transplanted rats was occluded for 30 min. Infarct size was measured after 24 h of reperfusion, while signaling pathways were evaluated after 15 min of reperfusion. Intestinal resistance, plasma concentration of LPS (lipopolysaccharides), activation of NF-κB and Akt and composition of the microbiota were also measured. Our results demonstrate a larger infarct size in animals transplanted with the dysbiotic microbiota without probiotics compared to the other groups, including those that received the dysbiotic microbiota with probiotics. This increase in infarct size correlates with a higher firmicutes/bacteroidetes ratio, NF-kB phosphorylation and plasma LPS concentration, and a decrease in intestinal barrier resistance and Akt. These results indicate that dysbiotic microbiota promotes an increase in infarct size, an effect that probiotics can attenuate., (© 2022. The Author(s).)

Certain lactic acid bacteria (LAB) are associated with immune modulatory activities including down-regulation of pro-inflammatory gene transcription and expression. While host antigen-presenting cells (APCs) and intestinal epithelial cells (IEC) can interact directly with both pathogenic and commensal bacteria through innate immune pattern recognition receptors, recent evidence indicates indirect communication through secreted molecules is an important inter-domain communication mechanism. This communication route may be especially important in the context of IEC and APC interactions which shape host immune responses within the gut environment. We have previously shown that the Lacticaseibacillus rhamnosus R0011 secretome (LrS) dampens pro-inflammatory gene transcription and mediator production from Tumor Necrosis Factor-α and Salmonella enterica serovar Typhimurium secretome (STS)-challenged HT-29 IECs through the induction of negative regulators of innate immunity. However, many questions remain about interactions mediated through these bacterial-derived soluble components and the resulting host immune outcomes in the context of IEC and APC interactions. In the present study, we examined the ability of the LrS to down-regulate pro-inflammatory gene transcription and cytokine production from STS-challenged T84 human IEC and THP-1 human monocyte co-cultures. Cytokine and chemokine profiling revealed that apically delivered LrS induces apical secretion of macrophage inhibitory factor (MIF) and down-regulates STS-induced pro-inflammatory mediator secretion into the apical and basolateral chambers of the T84/THP-1 co-culture. Transcriptional profiling confirmed these results, as the LrS attenuated STS challenge-induced CXCL8 and NF κ B1 expression in T84 IECs and THP-1 APCs. Interestingly, the LrS also reversed STS-induced damage to monolayer transepithelial resistance (TER) and permeability, results which were confirmed by ZO-1 gene expression and immunofluorescence visualization of ZO-1 expression in T84 IEC monolayers. The addition of a MIF-neutralizing antibody abrogated the ability of the LrS to reverse STS-induced damage to T84 IEC monolayer integrity, suggesting a novel role for MIF in maintaining IEC barrier function and integrity in response to soluble components derived from LAB. The results presented here provide mechanistic evidence for indirect communication mechanisms used by LAB to modulate immune responses to pathogen challenge, using in vitro approaches which allow for IEC and APC cell communication in a context which more closely mimics that which occurs in vivo ., Competing Interests: Authors CM and TT were employed in the Research and Development sector of Lallemand Health Solutions Inc. Author CM was employed by the NutraPharma Consulting Services, Inc. Author TT was employed by the Lallemand Bio-Ingredients, Inc. The remaining authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2022 Jeffrey, MacPherson, Tompkins and Green-Johnson.)

A growing body of evidence supports a role of the gut microbiota in regulating diverse physiological processes, including neural function and metabolism via the gut-brain axis. Infantile spasms syndrome is an early-onset epileptic encephalopathy associated with perturbed brain mitochondrial bioenergetics. Employing a neonatal rat model of infantile spasms, mitochondria respirometry and biochemical analyses, the present study reveals that gut microbiota manipulation by diet, antibiotics and probiotics have the potential to enhance hippocampal mitochondrial bioenergetics. Although preliminary in nature, our data reveal that microbial manipulation that regulates brain mitochondrial function may be a novel strategy for the treatment of epileptic disorders., (Copyright © 2022 Elsevier B.V. All rights reserved.)

Infantile spasms syndrome (IS) is a devastating early-onset epileptic encephalopathy associated with poor neurodevelopmental outcomes. When first-line treatment options, including adrenocorticotropic hormone and vigabatrin, are ineffective, the ketogenic diet (KD) is often employed to control seizures. Since the therapeutic impact of the KD is influenced by the gut microbiota, we examined whether targeted microbiota manipulation, mimicking changes induced by the KD, would be valuable in mitigating seizures. Employing a rodent model of symptomatic IS, we show that both the KD and antibiotic administration reduce spasm frequency and are associated with improved developmental outcomes. Spasm reductions were accompanied by specific gut microbial alterations, including increases in Streptococcus thermophilus and Lactococcus lactis. Mimicking the fecal microbial alterations in a targeted probiotic, we administered these species in a 5:1 ratio. Targeted probiotic administration reduced seizures and improved locomotor activities in control diet-fed animals, similar to KD-fed animals, while a negative control (Ligilactobacillus salivarius) had no impact. Probiotic administration also increased antioxidant status and decreased proinflammatory cytokines. Results suggest that a targeted probiotic reduces seizure frequency, improves locomotor activity in a rodent model of IS, and provides insights into microbiota manipulation as a potential therapeutic avenue for pediatric epileptic encephalopathies.

Recent studies have shown promise for the use of probiotics in modulating behaviour through the microbiota-gut-brain axis. In the present study, we assessed the impact of two probiotic strains in mitigating autism-related symptomology in the BTBR T + Itpr3 tf /J mouse model of autism spectrum disorder (ASD). Male juvenile BTBR mice were randomized into: (1) control, (2) Lr probiotic (1 × 10 9 CFU/mL Lacticaseibacillus rhamnosus HA-114), and (3) Ls probiotic groups (1 × 10 9 CFU/mL Ligilactobacillus salivarius HA-118) (n = 18-21/group), receiving treatments in drinking water for 4 weeks. Gut microbiota profiling by 16S rRNA showed Lr , but not Ls supplementation, to increase microbial richness and phylogenetic diversity, with a rise in potential anti-inflammatory and butyrate-producing taxa. Assessing serum and brain metabolites, Lr and Ls supplementation produced distinct metabolic profiles, with Lr treatment elevating concentrations of potentially beneficial neuroactive compounds, such as 5-aminovaleric acid and choline. As mitochondrial dysfunction is often observed in ASD, we assessed mitochondrial oxygen consumption rates in the prefrontal cortex and hippocampus. No differences were observed for either treatment. Both Lr and Ls treatment reduced behavioural deficits in social novelty preference. However, no changes in hyperactivity, repetitive behaviour, and sociability were observed. Results show Lr to impart positive changes along the microbiota-gut-brain axis, exhibiting beneficial effects on selected behaviour, gut microbial diversity, and metabolism in BTBR mice.

Exposure to stress during critical periods of development-such as puberty-is associated with long-term disruptions in brain function and neuro-immune responsivity. However, the mechanisms underlying the effect of stress on the pubertal neuro-immune response has yet to be elucidated. Therefore, the objective of the current study was to investigate the effect antimicrobial and lipopolysaccharide (LPS) treatments on acute immune responsivity in pubertal male and female mice. Moreover, the potential for probiotic supplementation to mitigate these effects was also examined. 240 male and female CD1 mice were treated with one week of antimicrobial treatment (mixed antimicrobials or water) and probiotic treatment ( L. rhamnosis R0011 and L. helveticus R0052 or L. helveticus R0052 and B. longum R0175) or placebo at five weeks of age. At six weeks of age (pubertal stress-sensitive period), the mice received a single injection of LPS or saline. Sickness behaviours were assessed, and mice were euthanized 8 h post-injection. Brain, blood, and intestinal samples were collected. The results indicated that the antimicrobial treatment reduced sickness behaviours, and potentiated LPS-induced plasma cytokine concentrations and pro-inflammatory markers in the pre-frontal cortex (PFC) and hippocampus, in a sex-dependent manner. However, probiotics reduced LPS-induced plasma cytokine concentrations along with hippocampal and PFC pro-inflammatory markers in a sex-dependent manner. L. rhamnosis R0011 and L. helveticus R0052 treatment also mitigated antimicrobial-induced plasma cytokine concentrations and sickness behaviours. These findings suggest that the microbiome is an important modulator of the pro-inflammatory immune response during puberty., Competing Interests: None., (© 2022 Published by Elsevier Ltd.)

Probiotics are increasingly administered to premature infants to prevent necrotizing enterocolitis and neonatal sepsis. However, their effects on gut microbiome assembly and immunity are poorly understood. Using a randomized intervention trial in extremely premature infants, we tested the effects of a probiotic product containing four strains of Bifidobacterium species autochthonous to the infant gut and one Lacticaseibacillus strain on the compositional and functional trajectory of microbiome. Daily administration of the mixture accelerated the transition into a mature, term-like microbiome with higher stability and species interconnectivity. Besides infant age, Bifidobacterium strains and stool metabolites were the best predictors of microbiome maturation, and structural equation modeling confirmed probiotics as a major determinant for the trajectory of microbiome assembly. Bifidobacterium-driven microbiome maturation was also linked to an anti-inflammatory intestinal immune milieu. This demonstrates that Bifidobacterium strains are ecosystem engineers that lead to an acceleration of microbiome maturation and immunological consequences in extremely premature infants., Competing Interests: Declaration of interests T.A.T. was the Research Director at Lallemand Health Solutions, the manufacturers of FloraBABY. The other authors declare no competing interests., (Copyright © 2022 Elsevier Inc. All rights reserved.)

Background: Infantile spasms syndrome (IS) is a type of epilepsy affecting 1.6 to 4.5 per 10,000 children in the first year of life, often with severe lifelong neurodevelopmental consequences. Only two first-line pharmacological treatments currently exist for IS and many children are refractory to these therapies. In such cases, children are treated with the ketogenic diet (KD). While effective in reducing seizures, the diet can result in dyslipidemia over time., Methods: Employing a neonatal Sprague-Dawley rat model of IS, we investigated how the KD affects hepatic steatosis and its modulation by a defined probiotic blend. A combination of multiple readouts, including malondialdehyde, fatty acid profiles, lipid metabolism-related enzyme mRNA expression, mitochondrial function, histone deacetylase activity, cytokines and chemokines were evaluated using liver homogenates., Findings: The KD reduced seizures, but resulted in severe hepatic steatosis, characterized by a white liver, triglyceride accumulation, elevated malondialdehyde, polyunsaturated fatty acids and lower acyl-carnitines compared to animals fed a control diet. The KD-induced metabolic phenotype was prevented by the co-administration of a blend of Streptococcus thermophilus HA-110 and Lactococcus lactis subsp. lactis HA-136. This probiotic blend protected the liver by elevating pAMPK-mediated signaling and promoting lipid oxidation. The strains further upregulated the expression of caspase 1 and interleukin 18, which may contribute to their hepatoprotective effect in this model., Interpretation: Our results suggest that early intervention with probiotics could be considered as an approach to reduce the risk of hepatic side effects of the KD in children who are on the diet for medically indicated reasons., Funding: This study was funded by the Alberta Children's Hospital Research Institute and Mitacs Accelerate Program (IT16942)., Competing Interests: Declaration of interests C.M. received an Alberta Children's Hospital Research Institute Trainee Travel Award that provided payment for hotel and travel for meeting. T.A.T sits as a FSHN External Advisory Board Member (unpaid) of University of Florida and Advisory Council Member (unpaid) of V1 Studio-Concordia University. No conflicts of interest exist for any of the authors., (Copyright © 2022 The Authors. Published by Elsevier B.V. All rights reserved.)

2'-fucosyllactose (2'FL) is one of the most abundant oligosaccharides in human milk, with benefits on neonatal health. Previous results point to the inability of the fecal microbiota from some infants to ferment 2'FL. We evaluated a probiotic formulation, including the strains Lactobacillus helveticus Rosell ® -52 (R0052), Bifidobacterium longum subsp. infantis Rosell ® -33 (R0033), and Bifidobacterium bifidum Rosell ® -71 (R0071), individually or in an 80:10:10 combination on the microbiota and 2'FL degradation. Independent batch fermentations were performed with feces from six full-term infant donors of two months of age (three breastfed and three formula-fed) with added probiotic formulation or the constituent strains in the presence of 2'FL. Microbiota composition was analyzed by 16S rRNA gene sequencing. Gas accumulation, pH decrease and 2'FL consumption, and levels of different metabolites were determined by chromatography. B. bifidum R0071 was the sole microorganism promoting a partial increase of 2'FL degradation during fermentation in fecal cultures of 2'FL slow-degrading donors. However, major changes in microbiota composition and metabolic activity occurred with L. helveticus R0052 or the probiotic formulation in cultures of slow degraders. Further studies are needed to decipher the role of the host intestinal microbiota in the efficacy of these strains.

Clostridioides difficile infection (CDI) is frequently associated with intestinal injury and mucosal barrier dysfunction, leading to an inflammatory response involving neutrophil localization and upregulation of pro-inflammatory cytokines. The severity of clinical manifestations is associated with the extent of the immune response, which requires mitigation for better clinical management. Probiotics could play a protective role in this disorder due to their immunomodulatory ability in gastrointestinal disorders. We assessed five single-strain and three multi-strain probiotics for their ability to modulate CDI fecal water (FW)-induced effects on T84 cells. The CDI-FW significantly ( p < 0.05) decreased T84 cell viability. The CDI-FW-exposed cells also exhibited increased pro-inflammatory cytokine production as characterized by interleukin (IL)-8, C-X-C motif chemokine 5, macrophage inhibitory factor (MIF), IL-32, and tumor necrosis factor (TNF) ligand superfamily member 8. Probiotics were associated with strain-specific attenuation of the CDI-FW mediated effects, whereby Saccharomyces boulardii CNCM I-1079 and Lacticaseibacillus rhamnosus R0011 were most effective in reducing pro-inflammatory cytokine production and in increasing T84 cell viability. ProtecFlor™, Lactobacillus helveticus R0052, and Bifidobacterium longum R0175 showed moderate effectiveness, and L. rhamnosus GG R0343 along with the two other multi-strain combinations were the least effective. Overall, the findings showed that probiotic strains possess the capability to modulate the CDI-mediated inflammatory response in the gut lumen., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2022 Gaisawat, Lopez-Escalera, MacPherson, Iskandar, Tompkins and Kubow.)

The fungus Candida albicans is an opportunistic pathogen that can exploit imbalances in microbiome composition to invade its human host, causing pathologies ranging from vaginal candidiasis to fungal sepsis. Bacteria of the genus Lactobacillus are colonizers of human mucosa and can produce compounds with bioactivity against C. albicans. Here, we show that some Lactobacillus species produce a small molecule under laboratory conditions that blocks the C. albicans yeast-to-filament transition, an important virulence trait. It remains unexplored whether the compound is produced in the context of the human host. Bioassay-guided fractionation of Lactobacillus-conditioned medium linked this activity to 1-acetyl-β-carboline (1-ABC). We use genetic approaches to show that filamentation inhibition by 1-ABC requires Yak1, a DYRK1-family kinase. Additional biochemical characterization of structurally related 1-ethoxycarbonyl-β-carboline confirms that it inhibits Yak1 and blocks C. albicans biofilm formation. Thus, our findings reveal Lactobacillus-produced 1-ABC can prevent the yeast-to-filament transition in C. albicans through inhibition of Yak1., (© 2021. The Author(s).)

Although breast milk is considered the gold standard of nutrition for infant feeding, some circumstances may make breastfeeding difficult. Several commercial milk preparations include synthetic human milk oligosaccharides (HMOs) in their composition. However, the effect of HMOs on the establishment of the intestinal microbiota remains incompletely understood. Independent batch fermentations were performed with feces from six full-term infant donors of two months of age (three breastfed and three formula-fed, exclusively) in the presence of 2'fucosyllactose (2'FL), one of the most abundant HMOs in human milk. Microbiota composition was analyzed by 16S rRNA gene sequencing at baseline and at 24 h of incubation. The 2'FL consumption, gas accumulation, and levels of different metabolites were determined by chromatography. Microbiota profiles at baseline were clearly influenced by the mode of feeding and by the intrinsic ability of microbiotas to degrade 2'FL. The 2'FL degradation rate clustered fecal cultures into slow and fast degraders, regardless of feeding type, this being a determinant factor influencing the evolution of the microbiota during incubation, although the low number of donors precludes drawing sound conclusions. More studies are needed to decipher the extent to which the early intervention with HMOs could influence the microbiota as a function of its ability to utilize 2'FL.

Emerging evidence highlighted the essential role played by the microbiota-gut-brain axis in maintaining human homeostasis, including nutrition, immunity, and metabolism. Much recent work has linked the gut microbiota to many psychiatric and neurodegenerative disorders such as depression, schizophrenia, and Alzheimer's disease. Shared gut microbiota alterations or dysbiotic microbiota have been identified in these separate disorders relative to controls. Much attention has focused on the bidirectional interplay between the gut microbiota and the brain, establishing gut dysbiotic status as a critical factor in psychiatric disorders. Still, the antibiotic-like effect of psychotropic drugs, medications used for the treatment of these disorders, on gut microbiota is largely neglected. In this review, we summarize the current findings on the impact of psychotropics on gut microbiota and how their antimicrobial potency can trigger dysbiosis. We also discuss the potential therapeutic strategies, including probiotics, prebiotics, and fecal transplantation, to attenuate the dysbiosis related to psychotropics intake., (Copyright © 2020 Elsevier Inc. All rights reserved.)

A probiotic formulation combining Lactobacillus helveticus Rosell ® -52, Bifidobacterium infantis Rosell ® -33, and Bifidobacterium bifidum Rosell ® -71 with fructooligosaccharides, first commercialized in China, has been sold in over 28 countries since 2002. Clinical studies with this blend of strains were conducted mainly in pediatric populations, and most were published in non-English journals. This comprehensive review summarizes the clinical studies in infants and children to evaluate the efficacy of this probiotic for pediatric indications. Literature searches for pediatric studies on Biostime ® or Probiokid ® (non-commercial name) in 6 international and Chinese databases identified 28 studies, which were classified by indications. Twelve studies show that the probiotic significantly increases the efficacy of standard diarrhea treatment regardless of etiology, reducing the risk of unresolved diarrhea (RR 0.31 [0.23; 0.42]; p < 0.0001) by 69%. In eight studies, the probiotic enhanced immune defenses, assessed by levels of various immune competence and mucosal immunity markers (six studies), and reduced the incidence of common infections (two studies). The probiotic improved iron deficiency anemia treatment efficacy (three studies), reducing the risk of unresolved anemia by 49% (RR 0.51 [0.28; 0.92]; p = 0.0263) and significantly reducing treatment side effects by 47% (RR 0.53 [0.37; 0.77]; p = 0.0009). Other studies support further investigation into this probiotic for oral candidiasis, eczema, feeding intolerance in premature babies, or hyperbilirubinemia in newborns.

Helicobacter pylori is a prevalent bacterium that can cause gastric ulcers and cancers. Lactic acid bacteria (LAB) ameliorate treatment outcomes against H. pylori, suggesting that they could be a source of bioactive molecules usable as alternatives to current antibiotics for which resistance is mounting. We developed an in vitro framework to compare the anti- H. pylori properties of 25 LAB and their secretions against H. pylori . All studies were done at acidic and neutralized pH, with or without urea to mimic various gastric compartments. Eighteen LAB strains secreted molecules that curtailed the growth of H. pylori and the activity was urea-resistant in five LAB. Several LAB supernatants also reduced the urease activity of H. pylori . Pre-treatment of H. pylori with acidic LAB supernatants abrogated its flagella-mediated motility and decreased its ability to elicit pro-inflammatory IL-8 cytokine from human gastric cells, without reverting the H. pylori -induced repression of other pro-inflammatory cytokines. This study identified the LAB that have the most anti- H. pylori effects, decreasing its viability, its production of virulence factors, its motility and/or its ability to elicit pro-inflammatory IL-8 from gastric cells. Once identified, these molecules can be used as alternatives or complements to current antibiotics to fight H. pylori infections.

Scope: Probiotics exert immunomodulatory effects and may influence tryptophan metabolism in the host. Deficiency of nutrients related to C1 metabolism might stimulate inflammation by enhancing the kynurenine pathway. This study used Sprague Dawley rats to investigate whether a methyl-deficient diet (MDD) may influence tryptophan/kynurenine pathways and cytokines and whether probiotics can mitigate these effects., Methods and Results: Rats are fed a control or MDD diet. Animals on the MDD diet received vehicle, probiotics (L. helveticus R0052 and B. longum R0175), choline, or probiotics + choline for 10 weeks (n = 10 per group). Concentrations of plasma kynurenine metabolites and the methylation and inflammatory markers in plasma and liver are measured., Results: MDD animals (vs controls) show upregulation of plasma kynurenine, kynurenic acid, xanthurenic acid, 3-hydroxyxanthranilic acid, quinolinic acid, nicotinic acid, and nicotinamide (all p < 0.05). In the MDD rats, the probiotics (vs vehicle) cause lower anthranilic acid and a trend towards lower kynurenic acid and picolinic acid. Compared to probiotics alone, probiotics + choline is associated with a reduced enrichment of the bacterial strains in cecum. The interventions have no effect on inflammatory markers., Conclusions: Probiotics counterbalance the effect of MDD diet and downregulate downstream metabolites of the kynurenine pathway., (© 2021 The Authors. Molecular Nutrition & Food Research published by Wiley-VCH GmbH.)

Psychobiotics are considered among potential avenues for modulating the bidirectional communication between the gastrointestinal tract and central nervous system, defined as the microbiota-gut-brain axis (MGBA). Even though causality has not yet been established, intestinal dysbiosis has emerged as a hallmark of several diseases, including neuropsychiatric disorders (NPDs). The fact that the microbiota and central nervous system are co-developing during the first years of life has provided a paradigm suggesting a potential role of psychobiotics for earlier interventions. Studies in animal models of early-life stress (ELS) have shown that they can counteract the pervasive effects of stress during this crucial developmental period, and rescue behavioral symptoms related to anxiety and depression later in life. In humans, evidence from clinical studies on the efficacy of psychobiotics at improving mental outcomes in most NPDs remain limited, except for major depressive disorder for which more studies are available. Consequently, the beneficial effect of psychobiotics on depression-related outcomes in adults are becoming clearer. While the specific mechanisms at play remain elusive, the effect of psychobiotics are generally considered to involve the hypothalamic-pituitary-adrenal axis, intestinal permeability, and inflammation. It is anticipated that future clinical studies will explore the potential role of psychobiotics at mitigating the risk developing NPDs in vulnerable individuals or in the context of childhood adversity. However, such studies remain challenging at present in terms of design and target populations; the profound impact of stress on the proper development of the MGBA during the first year of life is becoming increasingly recognized, but the trajectories post-ELS in humans and the mechanisms by which stress affects the susceptibility to various NPDs are still ill-defined. As psychobiotics are likely to exert both shared and specific mechanisms, a better definition of target subpopulations would allow to tailor psychobiotics selection by aligning mechanistic properties with known pathophysiological mechanisms or risk factors. Here we review the available evidence from clinical and preclinical studies supporting a role for psychobiotics at ameliorating depression-related outcomes, highlighting the knowledge gaps and challenges associated with conducting longitudinal studies to address outstanding key questions in the field., (Copyright © 2020 Lallemand Health Solutions. Published by Elsevier Inc. All rights reserved.)

Objective: Adults with Prader-Willi syndrome (PWS) require less energy intake to maintain body weight than the general adult population. This, combined with their altered gastrointestinal transit time, may impact microbiota composition. The aim of the study was to determine if the fecal microbiota composition of adults with PWS differed from non-affected adults. Using usual diet/non-interventional samples, fecal microbiota composition was analyzed using 16S rRNA gene amplicon sequencing and data from adults with PWS were merged with four other adult cohorts that differed by geographical location and age. QIIME 2™ sample-classifier, machine learning algorithms were used to cross-train the samples and predict from which dataset the taxonomic profiles belong. Taxa that most distinguished between all datasets were extracted and a visual inspection of the R library PiratePlots was performed to select the taxa that differed in abundance specific to PWS., Results: Fecal microbiota composition of adults with PWS showed low Blautia and enhanced RF39 (phyla Tenericutes), Ruminococcaceae, Alistipes, Erysipelotrichacaea, Parabacteriodes and Odoribacter. Higher abundance of Tenericutes, in particular, may be a signature characteristic of the PWS microbiota although its relationship, if any, to metabolic health is not yet known.

Phascolarctobacterium faecium is a strict anaerobe belonging to the Firmicutes phylum that is found abundantly in the human gastrointestinal tract. Here, we report the complete genome sequence of P. faecium G 104, a strain isolated from a fresh stool sample from a healthy lean donor., (Copyright © 2021 Rachek et al.)

Few studies have focused on dose-response analyses of multi-strain probiotics in the general adult population. This study aimed at comparing how a low- and high-dose of a multi-strain probiotic supplement (containing Lactobacillus helveticus R0052, Lactobacillus rhamnosus R0011, Lactobacillus casei R0215, Pediococcus acidilactici R1001, Bifidobacterium breve R0070, Bifidobacterium longum ssp. longum BB536, Lactobacillus plantarum R1012, Lactococcus lactis ssp. lactis R1058) affected microbiota composition, transit persistence and safety in adults. After a 7-d baseline, participants were randomized to receive capsules containing 5 or 25 billion CFU, or placebo daily for 28 days, followed by a 7-d washout. Digestive health and general wellness were assessed. Fecal microbiota composition was analyzed using 16S rRNA gene amplicon sequencing and strain persistence, by qPCR. Participants' gastrointestinal and general wellbeing were unaffected. No adverse events were associated with either dose. Supplemented strains contributed to the Lactobacillus and Bifidobacterium genera detected in stool, with 0.40 ± 0.11% and 0.51 ± 0.26%, respectively, in the high-dose group. Strain-specific qPCR assays revealed variable levels of post-intervention persistence between strains. Sequencing and composition analyses using the 16S V4 region revealed a decrease in Holdemania and increase in Bacteroidales . The formulation was well tolerated in this sample of the general adult population, even at the higher dose. The strains appear to have influenced microbiota composition minimally, as expected in the absence of dysbiosis, and consistently with the dose administered. Overall, the results provide a rationale to study the effects this formulation on microbiota composition in individuals exhibiting dysbiosis associated with metabolic disorders or obesity.

Background: Probiotics may provide a benefit for adults with Prader-Willi syndrome (PWS) experiencing constipation. The primary aim was to determine if Bifidobacterium animalis ssp. lactis B94 (B. lactis B94) improves stool frequency, with secondary aims of stool form and gastrointestinal symptoms. Exploratory aims included diet quality and fecal microbiota composition., Methods: Following a 4-week baseline, 25 adults with PWS were randomized to consume B. lactis B94 by capsule (15 billion) or placebo for 4 weeks, followed by 4-week washout in a double-blind, crossover design. Stool frequency and Bristol Stool Form (BSF) were assessed daily, and Gastrointestinal Symptom Rating Scale (GSRS) and dietary intake (7-days food records), per period. Fecal microbiota per period was analyzed using 16S rRNA gene amplicon sequencing and taxa of interest by qPCR (n = 24)., Results: No adverse events were reported. Stool frequency at baseline (n = 25; 2.0 ± 0.1 stools/day), GSRS syndromes, and microbiota composition did not differ with the probiotic intervention overall; however, a delayed, carry-over effect on BSF types 6 and 7 was seen. Diet quality by HEI-2015 was 65.4 ± 8.5., Conclusion: In adults with PWS, B. lactis B94 exhibited little effect on laxation over 4 weeks; however, further research is needed., (© 2020 The Authors. Molecular Genetics & Genomic Medicine published by Wiley Periodicals LLC.)

Over the past decade, there has been increasing evidence highlighting the implication of the gut microbiota in a variety of brain disorders such as depression, anxiety, and schizophrenia. Studies have shown that depression affects the stability of gut microbiota, but the impact of antidepressant treatments on microbiota structure and metabolism remains underexplored. In this study, we investigated the in vitro antimicrobial activity of antidepressants from different therapeutic classes against representative strains of human gut microbiota. Six different antidepressants: phenelzine, venlafaxine, desipramine, bupropion, aripiprazole and (S)-citalopram have been tested for their antimicrobial activity against 12 commensal bacterial strains using agar well diffusion, microbroth dilution method, and colony counting. The data revealed an important antimicrobial activity (bacteriostatic or bactericidal) of different antidepressants against the tested strains, with desipramine and aripiprazole being the most inhibitory. Strains affiliating to most dominant phyla of human microbiota such as Akkermansia muciniphila, Bifidobacterium animalis and Bacteroides fragilis were significantly altered, with minimum inhibitory concentrations (MICs) ranged from 75 to 800 μg/mL. A significant reduction in bacterial viability was observed, reaching 5 logs cycle reductions with tested MICs ranged from 400 to 600 μg/mL. Our findings demonstrate that gut microbiota could be altered in response to antidepressant drugs.

The gut microbiome affects various physiological and psychological processes in animals and humans, and environmental influences profoundly impact its composition. Disorders such as anxiety, obesity, and inflammation have been associated with certain microbiome compositions, which may be modulated in early life. In 62 Long-Evans rats, we characterised the effects of lifelong Bifidobacterium longum R0175 and Lactobacillus helveticus R0052 administration-along with Western diet exposure-on later anxiety, metabolic consequences, and inflammation. We found that the probiotic formulation altered specific anxiety-like behaviours in adulthood. We further show distinct sex differences in metabolic measures. In females, probiotic treatment increased calorie intake and leptin levels without affecting body weight. In males, the probiotic seemed to mitigate the effects of Western diet on adult weight gain and calorie intake, without altering leptin levels. The greatest inflammatory response was seen in male, Western-diet-exposed, and probiotic-treated rats, which may be related to levels of specific steroid hormones in these groups. These results suggest that early-life probiotic supplementation and diet exposure can have particular implications on adult health in a sex-dependent manner, and highlight the need for further studies to examine the health outcomes of probiotic treatment in both sexes.

The microbiota of the mouth disperses into the lungs, and both compartments share similar phyla. Considering the importance of the microbiota in the maturation of the immunity and physiology during the first days of life, we hypothesized that primo-colonizing bacteria of the oral cavity may induce immune responses in bronchial epithelial cells. Herein, we have isolated and characterized 57 strains of the buccal cavity of two human newborns. These strains belong to Streptococcus , Staphylococcus , Enterococcus , Rothia and Pantoea genera, with Streptococcus being the most represented. The strains were co-incubated with a bronchial epithelial cell line (BEAS-2B), and we established their impact on a panel of cytokines/chemokines and global changes in gene expression. The Staphylococcus strains, which appeared soon after birth, induced a high production of IL-8, suggesting they can trigger inflammation, whereas the Streptococcus strains were less associated with inflammation pathways. The genera Streptococcus , Enterococcus and Pantoea induced differential profiles of cytokine/chemokine/growth factor and set of genes associated with maturation of morphology. Altogether, our results demonstrate that the microorganisms, primo-colonizing the oral cavity, impact immunity and morphology of the lung epithelial cells, with specific effects depending on the phylogeny of the strains.

In the absence of established best practice standards in the probiotic field for reducing the risk of bacterial transfer between experimental groups, we developed protocols and methods to ensure the highest quality and interpretability of results from animal studies, even when performed in non-conventional animal care facilities. We describe easily implementable methods for reducing cross-contamination during animal housing, behavioural testing, and euthanasia, along with highlighting protocols for contamination detection in experimental subjects and laboratory areas using qPCR. In light of the high cross-contamination risks between animals during experiments involving probiotics, constant vigilance in animal care and research protocols is critical to ensure valid and reliable research findings.

Recent evidence suggests that lactic acid bacteria communicate with host cells via secretome components to influence immune responses but less is known about gut-pathogen secretomes, impact of lactic acid bacteria secretomes on host-pathogen interactions, and the mechanisms underlying these interactions. Genome-wide microarrays and cytokine profiling were used to interrogate the impact of the Lactobacillus rhamnosus R0011 secretome (LrS) on TNF-α and Salmonella enterica subsp. enterica serovar Typhimurium secretome (STS)-induced outcomes in human intestinal epithelial cells. The LrS attenuated both TNF-α- and STS-induced gene expression involved in NF-κB and MAPK activation, as well as expression of genes involved in other immune-related signaling pathways. Specifically, the LrS induced the expression of dual specificity phosphatase 1 ( DUSP1 ), activating transcription factor 3 ( ATF3 ), and tribbles pseudokinase 3 ( TRIB3 ), negative regulators of innate immune signaling, in HT-29 intestinal epithelial cells challenged with TNF-α or STS. TNF-α- and STS-induced acetylation of H3 and H4 histones was attenuated by the LrS, as was the production of TNF-α- and STS-induced proinflammatory cytokines and chemokines. Interestingly, the LrS induced production of macrophage migration inhibitory factor (MIF), a cytokine involved in host-microbe interactions at the gut interface. We propose that the LrS attenuates proinflammatory mediator expression through increased transcription of negative regulators of innate immune activity and changes in global H3 and H4 histone acetylation. To our knowledge, these findings provide novel insights into the complex multifaceted mechanisms of action behind secretome-mediated interdomain communication at the gut-mucosal interface., (Copyright © 2020 by The American Association of Immunologists, Inc.)

Specific probiotic strains can alleviate the gastrointestinal (GI) symptoms and psychiatric comorbidities of irritable bowel syndrome (IBS). In this randomized, double-blind, placebo-controlled study, the efficacy of Lactobacillus paracasei HA-196 ( L. paracasei ) and Bifidobacterium longum R0175 ( B. longum ) in reducing the GI and psychological symptoms of IBS was evaluated in 251 adults with either constipation (IBS-C), diarrhea (IBS-D), or mixed-pattern (IBS-M). Following a 2-week run-in period, participants were randomized to one of three interventions: L. paracasei ( n = 84), B. longum ( n = 83) or placebo ( n = 81). IBS symptoms, stool frequency and consistency and quality of life were assessed by questionnaires. The differences from baseline in the severity of IBS symptoms at 4 and 8 weeks were similar between groups. Participants in this study were classified, after randomization, into subtypes according to Rome III. Within the L. paracasei group, complete spontaneous and spontaneous bowel movement frequency increased in participants with IBS-C ( n = 10) after 8 weeks of supplementation (both p < 0.05) and decreased in participants with IBS-D ( n = 10, p = 0.013). Both L. paracasei and B. longum supplementation improved the quality of life in emotional well-being and social functioning compared with baseline (all p < 0.05). In conclusion, L. paracasei and B. longum may reduce GI symptom severity and improve the psychological well-being of individuals with certain IBS subtypes.

Background: Higher protein intakes may help reduce sarcopenia and facilitate recovery from illness and injury in older adults. However, high-protein diets (HPDs) including animal-sourced foods may negatively perturb the microbiota, and provision of probiotics and prebiotics may mitigate these effects., Objective: The aim of this study was to examine the effects of HPD, with and without a probiotic and/or prebiotic, on gut microbiota and wellness in older women., Design: We conducted an 18-week, double-blind, placebo-controlled, crossover study., Participants/setting: Participants were healthy, older women (mean age±standard deviation=73.7±5.6 years; n=26) recruited from Florida., Intervention: Participants received a weight-maintenance HPD for 2-week periods and the following, in random order: HPD alone (1.5 to 2.2 g/kg/day protein); HPD plus multistrain probiotic formulation (1.54×10 9 Bifidobacterium bifidum HA-132, 4.62×10 9 Bifidobacterium breve HA-129, 4.62×10 9 Bifidobacterium longum HA-135, 4.62×10 9 Lactobacillus acidophilus HA-122, and 4.62×10 9 Lactobacillus plantarum HA-119), HPD plus prebiotic (5.6 g inulin), and HPD plus synbiotic (probiotic plus inulin), separated by 2-week washouts. Stools were collected per period for quantitative polymerase chain reaction (strain recovery) and 16S ribosomal RNA gene amplicon sequencing analyses (microbiota profile). Measures of gastrointestinal and general wellness were assessed., Main Outcome Measures: Microbiota composition and probiotic strain recovery were measured., Statistical Analyses: Microbiota composition was analyzed by Wilcoxon signed-rank test and t test. Secondary outcomes were analyzing using generalized linear mixed models., Results: The microbiota profile demonstrated relative stability with the HPD; representation of Lactobacillus, Lactococcus, and Streptococcus were enhanced, whereas butyrate producers, Roseburia and Anaerostipes, were suppressed. Lactococcus was suppressed with synbiotic vs other HPD periods. Recovery was confirmed for all probiotic strains. Indicators of wellness were unchanged, with the exception of a minimal increase in gastrointestinal distress with inulin. Fat-free mass increased from baseline to study end., Conclusions: An HPD adhering to the recommended acceptable macronutrient distribution ranges maintains wellness in healthy older women and exerts minor perturbations to the microbiome profile, a group that may benefit from a higher protein intake. ClinicalTrials.gov ID: NCT #02445560., (Copyright © 2020 Academy of Nutrition and Dietetics. Published by Elsevier Inc. All rights reserved.)

Clostridium ( C. ) difficile -infection (CDI), a nosocomial gastrointestinal disorder, is of growing concern due to its rapid rise in recent years. Antibiotic therapy of CDI is associated with disrupted metabolic function and altered gut microbiota. The use of probiotics as an adjunct is being studied extensively due to their potential to modulate metabolic functions and the gut microbiota. In the present study, we assessed the ability of several single strain probiotics and a probiotic mixture to change the metabolic functions of normal and C. difficile -infected fecal samples. The production of short-chain fatty acids (SCFAs), hydrogen sulfide (H 2 S), and ammonia was measured, and changes in microbial composition were assessed by 16S rRNA gene amplicon sequencing. The C. difficile -infection in fecal samples resulted in a significant decrease ( p < 0.05) in SCFA and H 2 S production, with a lower microbial alpha diversity. All probiotic treatments were associated with significantly increased ( p < 0.05) levels of SCFAs and restored H 2 S levels. Probiotics showed no effect on microbial composition of either normal or C. difficile -infected fecal samples. These findings indicate that probiotics may be useful to improve the metabolic dysregulation associated with C. difficile infection.

Probiotic supplementation plays a key role in maintaining intestinal homeostasis due to its ability to modulate gut microbiota. Although their potential as potent antioxidants have previously been explored, their ability to affect the redox status in the gut lumen of healthy subjects or those with gastrointestinal (GI) disorders remains unclear. In our study, we assessed the ability of single strain and multispecies probiotic supplementation to cause a change in the redox status of normal fecal water and in Clostridium (C.) difficile -infected fecal water using a simulated gastrointestinal model. Changes in redox status were assessed by ferric-reducing antioxidant power (FRAP), 2',2'-diphenyl-1-picrylhydrazyl (DPPH), and iron and copper chelation assays. The findings from our study showed that in normal fecal water, probiotic supplements, apart from Lactobacillus ( L.) rhamnosus R0011, showed a significant increase in iron chelation ( p < 0.05), which was associated with lower FRAP and copper chelation. In C. difficile -infected fecal water, all probiotic supplements showed a significant increase in FRAP ( p < 0.05) and were associated with increased copper chelation. The DPPH assay showed no treatment effect in either fecal water. These findings suggest that C. difficile mediates dysregulation of redox status, which is counteracted by probiotics through ferric-reducing ability and copper chelation.

Microbial metabolism in the gut may alter human bile acid metabolism in a way that beneficially affects lipid homeostasis and therefore cardiovascular disease risk. Deconjugation of bile acids by microbes is thought to be key to this mechanism but has yet to be characterised in blood and stool while observing lipid markers. The aim of this study was to determine the effect of 3 different probiotic strains on plasma and stool bile acids in the context of lipid and glucose metabolism. In this 18-week, randomised, double-blind crossover study, healthy adults (53±8 years) with a high waist circumference underwent a 1-week pre-baseline period and were then randomised to receive 1 capsule/day of Bacillus subtilis R0179 (2.5×10 9 cfu/capsule; n=39), Lactobacillus plantarum HA-119 (5×10 9 cfu/capsule; n=38), Bifidobacterium animalis subsp. lactis B94 (5×10 9 cfu/capsule; n=37) or placebo for 6 weeks. Following a 3-week washout and second pre-baseline week, participants were crossed to the other intervention for 6 weeks followed by a 1-week post-intervention period. Blood and stool samples were collected at the beginning and end of each intervention to measure bile acids, serum lipid profiles, and glucose and insulin levels. Data from the placebo intervention were combined for all participants for analyses. In obese participants, the difference (final-baseline) in the sum of deconjugated plasma bile acids was greater with consumption of B. subtilis (691±378 nmol/l, P =0.01) and B. lactis (380±165 nmol/l, P =0.04) than with placebo (98±176 nmol/l, n=57). No significant differences were observed for any probiotics for stool bile acids, serum lipids, blood glucose or insulin. These data suggest that B. subtilis and B. lactis had no effect on glucose metabolism or serum cholesterol but increased deconjugated plasma bile acids in obese individuals. Additional studies should be conducted to confirm these findings and explore potential mechanisms. This trial was registered at clinicaltrials.gov as NCT01879098.

Caspase-3 activation in the limbic system and depressive-like symptoms are observed after an acute myocardial infarction (MI) and studies suggest that inflammation may play a significant role. Combined treatment with the probiotic strains Bifidobacterium longum and Lactobacillus helveticus in rats has been shown to attenuate caspase-3 activation and depressive-like behaviour together with a reduction in pro-inflammatory cytokines. The present study was designed to determine the respective contribution of these two strains on caspase-3 activity in the limbic system and on depressive-like behaviour. Sprague-Dawley rats were assigned to one of four groups: Vehicle, L. helveticus R0052, B. longum R0175 and L. salivarius HA-118, administered orally for 14 days (109CFU daily) before inducing MI by occlusion of the left anterior descending artery for 40 min followed by 14 days of reperfusion. Animals were then tested for socialisation, passive avoidance and forced swim test to assess depressive-like behaviour. At day 18 the animals were sacrificed; infarct size was estimated, plasma C-reactive protein concentration and brain caspase-3 activity were measured. Results indicated that infarct size did not vary across the different treatments. Rats treated with B. longum spent more time socializing, learned more rapidly the passive avoidance test and spent less time immobile in the forced swim test compared to the vehicle groups. Caspase-3 activity and plasma C-reactive protein concentrations were reduced in the lateral and medial amygdala as well as in the dentate gyrus of B. longum-supplemented animals. The only significant effect in the two groups receiving Lactobacilli compared to vehicle was that rats receiving L. salivarius learned more rapidly in the step-down passive avoidance test. In conclusion, most of the beneficial effects that we previously reported with the combination of two probiotic strains in our experimentation regarding post-myocardial infarction depression are related to Bifidobacterium longum., Competing Interests: AT and TAT have read the journal's policy and the authors of this manuscript have the following competing interests: AT is the scientific writer for Lallemand and TAT is the Research Director from Lallemand. There are no patents, products in development or marketed products associated with this research to declare. This commercial affiliation does not alter the authors' adherence to PLOS ONE policies on sharing data and materials.