Search

This study aimed to explore the effects and differences of conjugated linoleic acid (CLA)-producing Bifidobacterium longum on the alleviation of dextran sulfate sodium (DSS)-induced colitis and to explore its patterns. Different B. longum strains were administered at 109 cfu/day 7 days before DSS treatment. B. longum CCFM681 significantly increased goblet cells, mucin2 (MUC2), claudin-3, α-catenin1, and ZO-1, but neither B. longum CCFM760 nor B. longum CCFM642 had those protective effects. Interleukin-6 (IL-6) and tumor necrosis factor-alpha (TNF-α) were downregulated, while IL-10 was upregulated by B. longum CCFM681 but neither by B. longum CCFM760 nor by B. longum CCFM642. Moreover, B. longum CCFM681 treatment inhibited the toll-like receptor-4 (TLR4)/nuclear factor kappa-B (NF-κB) pathway. Furthermore, B. longum CCFM681 treatment rebalanced gut microbiota via regulating the diversity and key microorganisms. Colonic CLA concentrations in mice fed with B. longum CCFM681 were significantly higher than that of DSS-exposed mice, while those in B. longum CCFM760 and B. longum CCFM642 groups showed insignificant difference compared with the DSS group. Moreover, CLA showed a significantly positive correlation with the effectiveness of relieving colitis. B. longum CCFM681 alleviated colitis by protecting the intestinal mechanical barrier, modulating the gut microbiota, and inhibiting the TLR4/NF-κB pathway and associated pro-inflammatory cytokines. These results will help the clinical trials of probiotics and the development of functional products for colitis.

A linoleate isomerase complex including myosin-cross-reactive antigen, short-chain dehydrogenase/oxidoreductase, and acetoacetate decarboxylase has been confirmed as the pivotal factor for conjugated linoleic acid (CLA) production in Lactobacillus plantarum. However, its role in the metabolism and health-associated benefits of Lactobacillus remain unclear. In the current study, the mild type, knockout, and complemented mutants of the linoleate isomerase complex of L. plantarum ZS2058 were used to investigate those putative effects. The metabonomic results showed that a linoleate isomerase complex could significantly influence the glycol-metabolism, lipid metabolism, and antioxidant compounds. Especially, with the stress of linoleic acid, linoleate isomerase complex knockout mutants induced the increase of several antioxidant compounds, such as glutamic acid, glycine, l-cysteine, glycerol, and l-sorbosone. Moreover, the linoleate isomerase complex played a pivotal role in ameliorating DSS-induced colitis. The knockout mutants showed effects similar to those in the DSS group, whereas complementation of the corresponding gene in the knockout mutants could restore the anti-inflammatory activity, wherein the integrity of a mucus layer was repaired, the level of pro-inflammatory cytokines decreased, and the amount of anti-inflammatory cytokines increased significantly. All the results indicated that the linoleate isomerase complex plays a key role in CLA production and metabolism as well as the health-associated benefits of L. plantarum ZS2058. These results are conducive to promote clinical trials and product development of probiotics for colitis.

This study was designed to explore the effects and discrepancy of different CLA-producing Bifidobacterium pseudocatenulatum on relieving colitis and to investigate the potential mechanisms. B. pseudocatenulatum MY40C and CCFM680 were administered to mice with DSS-induced colitis. The content of tight junction proteins and mucin2 was significantly upregulated. TNF-α and IL-6 were downregulated, while IL-10 and PPAR-γ were upregulated. TLR4/NF-κB pathway activation was significantly inhibited. Moreover, each treated strain increased Allobaculum and decreased Sutterella, Bacteroides, and Oscillospira. The colonic conjugated linoleic acid (CLA) concentrations were significantly and positively correlated with the effectiveness of strain in relieving colitis. In conclusion, MY40C and CCFM680 supplementation alleviated DSS-induced colitis by protecting intestinal mechanical barrier, modulating gut microbiota, blocking proinflammatory cytokines, and inhibiting TLR4/NF-κB pathway. These results are conducive to promote clinical trials and product development of probiotics for colitis.

To investigate the specific functions of conjugated fatty acids (CFAs) produced by the probiotic bacterium, α-linolenic acid was isomerized by Lactobacillus plantarum ZS2058, and two different conjugated linolenic acid (CLNA) isomers were successfully isolated: c9, t11, c15-CLNA (CLNA1) and t9, t11, c15-CLNA (CLNA2). The effects and mechanism of CLNA crude extract and individual isomers on colitis were explored. CLNA significantly inhibited weight loss, the disease activity index, and colon shortening. Additionally, CLNA alleviated histological damage, protected colonic mucus layer integrity, and significantly upregulated the concentration of tight junction proteins (ZO-1, occludin, E-cadherin 1, and claudin-3). CLNA significantly attenuated the level of proinflammatory cytokines (TNF-α, IL-1β, and IL-6) while upregulating the expression of the colonic anti-inflammatory cytokine IL-10 and nuclear receptor peroxisome-activated receptor-γ. Moreover, CLNA increased the activity of oxidative stress-related enzymes (SOD, GSH, and CAT), and the myeloperoxidase activity was significantly decreased by CLNA. Meanwhile, the concentrations of CLNA in the liver and conjugated linoleic acid in the colonic content were significantly increased because of the treatment of CLNA. Furthermore, CLNA could rebalance the intestinal microbial composition of colitis mice, including increasing the α-diversity. CLNA1 and CLNA2 increased the abundance of Ruminococcus and Prevotella, respectively.

A linoleate isomerase complex including myosin-cross-reactive antigen, short-chain dehydrogenase/oxidoreductase, and acetoacetate decarboxylase has been confirmed as the pivotal factor for conjugated linoleic acid (CLA) production in

peer-reviewed Prebiotics may improve ageing-related dysbiosis. Milk is a source of nutrients including oligosaccharides whose prebiotic potential remains largely unexplored. We used a murine model to explore the effect of milk products on high diversity and lower diversity faecal microbiota from healthy and frail elderly subjects, respectively. Mice were treated with antibiotics and subsequently "humanised" with human faecal microbiota. The mice received lactose-free or whole milk, glycomacropeptide, or soy protein (control) supplemented diets for one month. The faecal microbiota was analysed by 16S rRNA gene amplicon sequencing. Lactose-free milk diet was as efficient as the control diet in retaining faecal microbiota diversity in mice. Both milk diets had a significant effect on the relative abundance of health-relevant taxa (e.g. Ruminococcaceae, Lachnospiraceae). The glycomacropeptide prebiotic activity previously observed in vitro was not replicated in vivo. However, these data indicate the novel prebiotic potential of bovine milk for human nutrition. ACCEPTED peer-reviewed

To investigate the specific functions of conjugated fatty acids (CFAs) produced by the probiotic bacterium, α-linolenic acid was isomerized by

Dietary supplementation with conjugated linoleic acid (CLA) has been reported to alleviate the effect of colitis in mice, but the mechanisms involved need further exploration. The study aimed to investigate how orally administered CLA alleviates dextran sulfate sodium (DSS)-induced colitis in mice. CLA was administered in five different doses: 40, 20, 10, 5, and 2.5 mg/day. Doses of CLA at 10 mg/day and higher alleviated colitis symptoms and reduced inflammation induced by DSS, in which 40, 20, and 10 mg/day CLA significantly increased the concentration of mucin2 and goblet cells, but neither 5 mg/day CLA nor 2.5 mg/day CLA had any effects. Meanwhile, 40 and 20 mg/day CLA treatments significantly upregulated the concentration of tight junction proteins (ZO-1, occludin, and claudin-3) and ameliorated epithelial apoptosis caused by DSS. Moreover, oxidative-stress-related enzymes (superoxide dismutase, glutathione peroxidase, and catalase) and inflammatory cytokines [tumor necrosis factor-α, interleukin (IL)-10, and IL-6] were modulated by 40 and 20 mg/day CLA. Furthermore, 40 mg/day CLA rebalanced the gut microbiota damaged by DSS, including reducing Bacteroides and increasing Bifidobacterium and Odoribacter. In conclusion, CLA supplementation alleviated DSS-induced colitis in a dose-dependent manner by modulating inflammatory cytokines and oxidation stress, maintaining the mucosal barrier, and reverting microbiota changes.

The potential of milk-derived glycomacropeptide (GMP) and lactose for modulating the human gut microbiota of older people, in whom loss of diversity correlates with inferior health, was investigated. We used an in vitro batch fermentation (artificial colon model) to simulate colonic fermentation processes of two GMP products, i.e., a commercially available GMP concentrate and a semipurified GMP concentrate, and lactose. Faecal samples were collected from healthy and frail older people. Samples were analyzed by Illumina Miseq sequencing of rRNA gene amplicons. The commercial GMP preparation had a positive effect on the growth of Coprococcus and Clostridium cluster XIVb and sustained a higher faecal microbiota diversity compared to control substrates or lactose. Lactose fermentation promoted the growth of Proteobacteria including Escherichia/Shigella. This work provides an in-depth insight on the potential of GMP and lactose for modulating the gut microbiota and contributes more evidence confirming the prebiotic activity of GMP.