The role of neurotrophic factors, oxidative stress, and inflammation in the pathogenesis of Alzheimer’s disease (AD) has been explored. Animal studies have reported the positive effects of probiotics on these factors. Some clinical studies also support the potential role of probiotics in improving cognitive function via the gut–brain axis in older adults. However, clinical experimental studies evaluating the efficacy of probiotics targeting the neurotrophic factors and inflammatory biomarkers, particularly among AD patients, remain very limited. In this randomized, double-blinded, active-controlled trial, we used multi-strain probiotic supplements, including Bifidobacterium longum subsp. infantis BLI-02, B. breve Bv-889, B. animalis subsp. lactis CP-9, B. bifidum VDD088, and Lactobacillus plantarum PL-02 as the intervention. Participants were divided into an active control group (received probiotic supplements containing 5 × 10⁷ colony-forming units per day, CFU/day) and a treatment group (1 × 10¹⁰ CFU/day). Student’s t test was applied as the main method of statistical analysis. After 12 weeks of intervention, the treatment group demonstrated a 36% increase in serum brain-derived neurotrophic factor (BDNF) (* p = 0.005), a reduction in IL-1β (* p = 0.041), and an increase in antioxidant superoxide dismutase (SOD) (* p = 0.012). No significant change was found in the active control group. A trend toward less cognitive deterioration was observed, but not statistically significant. In conclusion, this study presents evidence supporting the benefits of multi-strain probiotics in enhancing BDNF, ameliorating inflammation and oxidative stress in AD patients.

Bifidobacterium longum subsp. infantis BLI-02, Lactobacillus paracasei ET-66, Lactobacillus plantarum LPL28, and Lactobacillus acidophilus TYCA06, isolated from healthy breast milk, miso, and the healthy human gut, were assessed for safety in this study. BLI-02, LPL28, TYCA06, and ET-66 exhibited no antibiotic resistance and mutagenic activity in the Ames test at the highest dosage (5000 μg/plate). No genotoxicity was observed in micronucleus and chromosomal aberration assays in rodent spermatogonia at the maximum dosage of 10 g/kg body weight (BW). No acute and sub-chronic toxicity occurred in mice and rats at the maximum tested dosage of 10 g/kg BW and 1.5 g/kg BW, respectively. The lyophilized powder of these strains survived a low pH and high bile salt environment, adhering strongly to Caco-2 cells. Unique antimicrobial activities were noted in these strains, with BLI-02 demonstrating the best growth inhibition against Vibrio parahaemolyticus, LPL28 exhibiting the best growth inhibition against Helicobacter pylori, and ET-66 showing the best growth inhibition against Aggregatibacter actinomycetemcomitans. Based on the present study, the lyophilized powder of these four strains appears to be a safe probiotic supplement at tested dosages. It should be applicable for clinical or healthcare applications.

One-third of patients with end-stage chronic kidney disease (CKD) experience diabetic nephropathy (DN), which worsens the progression of renal dysfunction. However, preventive measures for DN are lacking. Lactobacillus acidophilus TYCA06, Bifidobacterium longum subsp. infantis BLI-02, and Bifidobacterium bifidum VDD088 probiotic strains have been demonstrated to delay CKD progression. This study evaluated their biological functions to stabilize blood-glucose fluctuations and delay the deterioration of renal function. The db/db mice were used to establish a DN animal model. This was supplemented with 5.125 × 10⁹ CFU/kg/day (high dose) or 1.025 × 10⁹ CFU/kg/day (low dose) mixed with probiotics containing TYCA06, BLI-02, and VDD088 for 8 weeks. Blood urea nitrogen (BUN), serum creatinine, blood glucose, and urine protein were analyzed. Possible mechanisms underlying the alleviation of DN symptoms by probiotic strains were evaluated through in vitro tests. Animal experiments revealed that BUN, serum creatinine, and blood glucose upon probiotic administration were significantly lower than in the control group. The rate of change of urine protein decreased significantly, and blood pressure, glucose tolerance, and renal fibrosis were improved. In vitro testing indicated that TYCA06 and BLI-02 significantly increased acetic acid concentration. TYCA06, BLI-02, and VDD088 were associated with better antioxidation, anti-inflammation, and glucose consumption activities relative to the control. A combination of the probiotics TYCA06, BLI-02, and VDD088 attenuated renal function deterioration and improved blood-glucose fluctuation in a diabetes-induced CKD mouse model.

Obesity is referred to as a condition in which excess body fat has accumulated to an extent that it causes negative impacts on health. The formation of body fat is regulated by complicated networks in relation to energy metabolism, and gut microbiota have been regarded as a key player. Studies have shown that supplements of probiotics provide benefits to health, including an improvement in metabolic syndrome and the control of body weight. In the present study, three probiotic strains, AP-32, bv-77, and CP-9, stood out from nine candidates using a lipid consumption assay, and were subsequently introduced to further animal tests. A rodent model of obesity was induced by a high-fat diet (HFD) in Sprague-Dawley (SD) rats, and three probiotic strains were administered either separately or in a mixture. A low dose (5 × 10⁹ CFU/kg/day) and a high dose (2.5 × 10¹⁰ CFU/kg/day) of probiotics were orally provided to obese rats. The bioeffects of the probiotic supplements were evaluated based on five aspects: (1) the body weight and growth rate; (2) ketone bodies, non-esterified fatty acids (NEFAs), and feed efficiency; (3) blood biochemistry; (4) fat content; and (5) gut microbiota composition. Our results demonstrated that the supplement of AP-32, CP-9, and bv-77 alleviated the increasing rate of body weight and prevented the elevation of NEFAs and ketone bodies in obese rats. Although the effect on fat content showed a minor improvement, the supplement of probiotics displayed significant improvements in HFD-induced poor blood biochemical characteristics, such as alanine aminotransferase (ALT), aspartate Transaminase (AST), and uric acid, within 4 weeks. Furthermore, the combined supplement of three strains significantly increased Akkermansia mucinphila as compared with three individual strains, while its enrichment was negatively correlated with NEFAs and energy metabolism. In general, a mixture of three probiotic strains delivered a better outcome than a single strain, and the high dose of supplements provided a more profound benefit than the low dose. In conclusion, three probiotic strains, AP-32, bv-77, and CP-9, can alleviate body fat formation in obese rats. Furthermore, a combined supplement of these three probiotic strains may have potential in treating or controlling metabolic disorders.

Probiotics are considered safe and beneficial to human health. However, the safety of Lactobacillus salivarius AP-32 and Bifidobacterium animalis CP-9 in infants has not been confirmed. This study was to assess the safety of long-term oral administration of L. salivarius AP-32 and B. animalis CP-9 in healthy infants compared with placebo. A three-arm, randomized, double-blind, placebo-controlled trial was conducted in healthy, full-term infants. Eighty-eight infants between 7 days and 2 months (60 ± 7 days) of age were selected and randomized to treatment with L. salivarius AP-32, B. animalis CP-9 or placebo for 4 months. The unblinding indicated subjects were randomized to receive B. animalis CP-9 (N = 28), L. salivarius AP-32 (N = 29), or placebo (N = 31). A total of 76 infants completed the 4-month treatment with fully compliance. The primary outcome was weight gain, with no significant difference in infant weight at 4 months when comparing AP-32 or CP-9 group with the placebo group, either. The head circumference and recumbent length of the CP-9 group were not significantly different from those of the placebo group. The recumbent length of the AP-32 group was slightly lower than that in the placebo group at month 4, but there was no difference between the two groups in head circumference. Overall, the growth trend of all treatments was similar without significant difference. Furthermore, there were no apparent differences between each group in digestive tolerance, the occurrence of adverse events, crying/fussing time and episodes, alpha diversity, and beta diversity. The CP-9 group showed a significant increase in the abundance of the Bacteroides genus, while the AP-32 group demonstrated a significant increase in the abundance of the Lactobacillus genus when comparing the two probiotic groups. Our study findings indicate that the oral administration of both AP-32 and CP-9 strains has a positive impact on the maintenance of a healthy gut flora in infants. Long-term use of L. salivarius AP-32 or B. animalis CP-9 is safe for infants from 7 days to 6 months of age.

Obesity is a worldwide health problem. Calorie-restricted diets constitute a common intervention for treating obesity. However, an improper calorie-restricted diet can lead to malnutrition, fatigue, poor concretion, muscle loss, and reduced exercise performance. Probiotics have been introduced as an alternative treatment for obesity. In the present study, we tested the weight loss and exercise performance enhancement effectiveness of probiotic strains of different origins, including four isolated from an Olympic weightlifting gold medalist (Bifidobacterium longum subsp. longum OLP-01, Lactobacillus plantarum PL-02, Lactobacillus salivarius subsp. salicinius SA-03, and Lactococcus lactis subsp. lactis LY-66). A high-fat diet (HFD) was used to induce obesity in 16 groups of mice (n = 8/group). The mice were administered probiotic supplements at a dosage of 4.1 × 10⁹ CFU/kg/day for 10 weeks. All probiotic supplementation groups showed a significant reduction in body weight and fat mass compared with the HFD group. TYCA06, CS-773, BLI-02, PL-02, bv-77, and OLP-01 were the most effective in facilitating weight loss and fat reduction, which may be due to fatty-acid absorbing activity. PL-02, LY-66, TYCA06, CS-773, and OLP-01 elevated the animals’ grip strength and exhaustive running duration. PL-02, LY-66, and OLP-01 increased tissue glycogen (liver and muscle) levels and muscle capillary density and reduced blood lactate production levels after exercise. In conclusion, OLP-01, PL-02, LY-66, TYCA06, and CS-773 were highly effective in enhancing weight loss and exercise performance. This study should be repeated on humans in the future to further confirm the findings.