Search

To improve the freeze-drying survival rate of Lactobacillus casei LTL1361 in the vacuum freeze-drying process, the single factor and Plackett-Burman designs were first conducted to verify the main factors affecting the freeze-drying survival rate of Lactobacillus casei LTL1361. According to the experimental results, the artificial network coupling genetic algorithm was constructed using the Box Behnken design. The artificial network coupled genetic algorithm (BP-GA) model was constructed to simulate and predict the lyophilized protective agent formulation of Lactobacillus casei LTL1361. The results showed that the three main factors affecting the lyophilisation survival rate of the strain were: Alginate, glutamic acid and mannitol, which were selected by single-factor and Plackett-Burman tests, and the three factors and the base skim milk were identified as the optimisation conditions for subsequent optimisation tests. The BP-GA model was used to find the optimum concentration of protectant for Lactobacillus casei LTL1361, which was 10.3% skim milk, 0.8% glutamic acid, 6.7% alginate and 4.0% mannitol, and the maximum lyophilisation survival rate of the strain was 89.56%. Using the BP-GA model, this study explored a probiotic lyophilisation protectant formulation with a high lyophilisation survival rate, and provided a reference for the preparation of lyophilised formulations of highly active strains and the development of commercial direct-injection ferments.

This research adopted the D-galactose induced senility mice as the research object, under the condition of constant energy control, different protein content of feeding groups was designed. Mice were under dietary intervention for 8 weeks, by analyzing the Morris water maze data, brain tissue slice and liver tissue antioxidant capacity to explore the anti-aging effect of protein nutrition in Guangxi longevity dietary patterns. The results showed that: Compared with the high (P/C=1/2), medium (P/C=1/3) and low (P/C=1/5) protein diet groups, the escape latency of mice in P/C=1/4 (protein/carbohydrate) group significantly decreased (P P/C=1/5 group > P/C=1/3 group > young control group > P/C=1/2 group > aging control group. In summary, mice in P/C=1/4 low-protein diet group can effectively resist the senior-induced injury of D-galactose, and maintain strong learning and memory ability and antioxidant ability, thus showing strong anti-aging effect. The results of this study would provide a theoretical basis for the relationship between dietary protein nutrition and health as well as longevity.

The activity of probiotic products would reduce to a certain extent during storage and in the gastrointestinal tract, resulting in weakened potential probiotic properties, in this study, Lactobacillus fermentum LTP1332 from the feces of centenarians in Bama, Guangxi was microencapsulated. In this experiment, gelatin (GEL) and chitosan (CS) were introduced for compounding based on sodium alginate (SA) and CaCl2 as the main wall materials. The key factors affecting the embedding rate were found by single-factor test, the radial basis function (RBF) was constructed by using Box-Behnken design (BBD), and the encapsulation process of Lactobacillus fermentum LTP1332 microcapsules was optimized by using genetic algorithms (GA). The optimized capsules were characterized using SEM scanning electron microscopy and other methods, and the in vitro simulated digestion tests was carried out. Results showed that, the optimum preparation parameters of the microcapsule were as follows: 2.210% sodium alginate, 4.451% CaCl2, 0.1% gelatin, 13.529 min curing time. Under such conditions, the measured average embedding rate was 95.08%±0.25%. The cell survival rate of CS-GEL-SA microcapsule under the optimized processing conditions could still reach 22.48%±0.78% after being treated with simulated gastric juice for 120 min. The maximum rate of probiotic release could be reached at 90 min of digestion with simulated intestinal juice, which had good intestinal solubility. Therefore, it is considered that the long-lived elderly source probiotic microcapsule prepared under this processing condition would have a good bacterial protection effect and good prospects in development and application.

Based on the previous study on the diet of the cohort of long-lived people in Guangxi, the recipes of long-lived people were summarized. In this study, eight representative dietary fiber complexes (DFC) with specific proportion in the recipes were extracted by ultrasonic assisted enzyme method, and the optimal conditions of extraction process were explored through single factor and response surface tests, the basic components and physical and chemical properties were analyzed. The results showed that the maximum yield of total dietary fiber (TDF) was 63.90%, which was basically consistent with the theoretical prediction when the addition of α-amylase was 0.3%, the ultrasonic power was 242 W, the liquid-solid ratio was 15 mL/g and the extraction temperature was 86 ℃. After optimization, the contents of protein, fat and other impurities in TDF decreased from (2.66%±0.12%) and (5.31%±0.14%) to (1.90%±0.08%) and (1.77%±0.26%) respectively, and the content of TDF increased significantly (P

IntroductionRecent evidence supports a role for the gut microbe-metabolites in longevity. However, the phenomenon of hypertension is more common in the longevity area and whether hypertension is associated with longevity remains unclear. Here, we hypothesize that the levels of gut microbiota, SCFAs, and urine metabolites were different between hypertension elderly and hypertension longevity.MethodsWe recruited 46 elderly volunteers from Donglan County, Guangxi, and 32 were selected and included in the experiment. The subjects with hypertension were divided into two groups according to age, Hypertension Elderly (HTE, aged 70.5 ± 8.59, n = 19) and Hypertension Longevity (HTL, aged 100 ± 5.72, n = 13). The gut microbiota, SCFAs, and urine metabolites were determined by three-generation 16S rRNA full-length sequencing, GC-MS, and 1H-NMR, respectively.ResultsCompared with the HTL group, the HTE group had higher levels of hypertension-related genera Klebsiella and Streptococcus, while having lower levels of the SCFA-producing genera Bacteroides, Faecalibacterium, and Alistipes. Based on LEFse analysis, Klebsiella pneumoniae, Lactobacillus gasseri, Streptococcus salivarius, Ruminococcus, Actinomyces, Rikenellaceae, f_Saccharimonadaceae, Clostridium perfringens, and Bacteroids, Faecalibacterium prausnitzii, Parabacteroides, Alistipes were biomarkers that showed significant differences between the groups. In addition, the microbial pathways associated with K. pneumoniae and E. coli may promote hypertension, while A. muciniphila may play a role in reversing the development of hypertension in long-lived elderly. Metabolomics revealed that HTL contained a lower concentration of fecal acetate and propionate than HTE, while it contained a higher concentration of serum acetate and urine acetate. Furthermore, their immune cells exhibited no significant changes in SCFAs receptors.ConclusionAlthough long-lived elderly have extremely high systolic blood pressure, their unique gut microbiota composition and efficient acetate absorption in the colon may offset the damages caused by hypertension and maintain healthy homeostasis.

In the protein nutrition strategy of middle-aged and elderly people, some believe that low protein is good for health, while others believe high protein is good for health. Facing the contradictory situation, the following hypothesis is proposed. There is a process of change from lower to higher ratio of protein nutritional requirements that are good for health in the human body after about 50 years of age, and the age at which the switch occurs is around 65 years of age. Hence, in this study, 50, 25-month-old male rats were randomly divided into five groups: Control (basal diet), LP (low-protein diet with a 30% decrease in protein content compared to the basal diet), HP (high-protein diet with a 30% increase in protein content compared to the basal diet), Model 1 (switched from LP to HP feed at week 4), and Model 2 (switched from LP to HP feed at week 7). After a total of 10 weeks intervention, the liver and serum samples were examined for aging-related indicators, and a newly comprehensive quantitative score was generated using principal component analysis (PCA). The effects of the five protein nutritional modalities were quantified in descending order: Model 1 > HP > LP > Control > Model 2. Furthermore, the differential metabolites in serum and feces were determined by orthogonal partial least squares discriminant analysis, and 15 differential metabolites, significantly associated with protein intake, were identified by Spearman’s correlation analysis (p < 0.05). Among the fecal metabolites, 10 were positively correlated and 3 were negatively correlated. In the serum, tyrosine and lactate levels were positively correlated, and acetate levels were negatively correlated. MetaboAnalyst analysis identified that the metabolic pathways influenced by protein intake were mainly related to amino acid and carbohydrate metabolism. The results of metabolomic analysis elucidate the mechanisms underlying the preceding effects to some degree. These efforts not only contribute to a unified protein nutrition strategy but also positively impact the building of a wiser approach to protein nutrition, thereby helping middle-aged and older populations achieve healthy aging.