Dyslipidemia, specifically abnormal levels of low-density lipoprotein cholesterol (LDL-C), is an important risk factor of cardiovascular disease. Evidence showing the promising abilities of probiotics to lower total cholesterol or LDL-C has, however, not yet convinced experts to recommend probiotic bacteria as treatment for blood lipid management. Therefore, there are opportunities for the development of new efficient cholesterol-lowering probiotics. Bile salt hydrolase (BSH) and feruloyl esterase (FAE) are bacterial enzymes proposed to explain the cholesterol-lowering capacity of some bacteria and have both been shown to be responsible for lipid reduction in vivo. Here, in order to select for cholesterol-lowering bacteria, 70 strains related to Lactobacillaceae were screened for BSH and FAE activities. Based on this two-way screening approach, two bacteria were selected and assessed for their capacity to assimilate cholesterol in vitro, another suggested mechanism. Lactobacillus acidophilus CL1285 showed BSH and FAE activity as well as capacity to assimilate cholesterol in vitro. Lactiplantibacillus plantarum CHOL-200 exhibited BSH activity and ability to assimilate cholesterol. These properties observed in vitro make both strains good probiotic candidates for the management of dyslipidemia. Further investigation is needed to assess their ability to reduce blood cholesterol in human trial.

Caenorhabditis elegans was recently shown to be a powerful model for studying and identifying probiotics with specific functions. Lactobacillus acidophilus CL1285, Lacticaseibacillus casei LBC80R, and Lacticaseibacillus rhamnosus CLR2, which are three bacteria that were marketed by Bio-K+, were evaluated using the nematode C. elegans to study fat accumulation, lifespan, and resistance to oxidative stress. Although the general effects of probiotics in terms of protection against oxidative stress were highlighted, the CL1285 strain had an interesting and specific feature, namely its ability to prevent fat accumulation in nematodes; this effect was verified by both the Oil Red and Nile Red methods. This observed phenotype requires daf-16 and is affected by glucose levels. In addition, in a daf-16- and glucose-dependent manner, CL1285 extended the lifespan of C. elegans; this effect was unique to CL1285 and not found in the other L. acidophilus subtypes in this study. Our findings indicate that L. acidophilus CL1285 impacts fat/glucose metabolism in C. elegans and provides a basis to further study this probiotic, which could have potential health benefits in humans and/or in mammals.

The health and balance of the gut microbiota are known to be linked to diet composition and source, with fermented products and dietary proteins potentially providing an exceptional advantage for the gut. The purpose of this study was to evaluate the effect of protein hydrolysis, using a probiotic beverage enriched with either cricket protein (CP) or cricket protein hydrolysates (CP.Hs), on the composition of the gut microbiota of rats. Taxonomic characterization of the gut microbiota in fecal samples was carried out after a 14-day nutritional study to identify modifications induced by a CP- and CP.H-enriched fermented probiotic product. The results showed no significant differences (p > 0.05) in the diversity and richness of the gut microbiota among the groups fed with casein (positive control), CP-enriched, and fermented CP.H-enriched probiotic beverages; however, the overall composition of the microbiota was altered, with significant modifications in the relative abundance of several bacterial families and genera. In addition, fermented CP.H-enriched probiotic beverages could be related to the decrease in the number of potential pathogens such as Enterococcaceae. The association of gut microbiota with the nutritional parameters was determined and the results showed that digestibility and the protein efficiency ratio (PER) were highly associated with the abundance of several taxa.

Clostridioides difficile infections (CDIs) continue to be a persistent healthcare concern despite newer antibiotic treatments, enhanced infection control practices, and preventive strategies focused on restoring the protective intestinal microbial barrier. Recent strides in gene sequencing research have identified many genes regulating diverse virulence factors for CDIs. These genes may be over- or under-expressed when triggered by various environmental and nutritional factors. The aims of this paper are to review the important genes involved in C. difficile pathogenesis and to identify modifiable environmental, nutritional, and other factors that may trigger the expression of these genes and thus offer new strategies to prevent CDIs.

Background: Abrupt dietary changes may disrupt gut microbiota populations and lead to gastrointestinal issues. This study aimed to determine the effects of live Bacillus pumilus SG154 or Lacticaseibacillus paracasei 327 postbiotic on fecal characteristics and microbiota populations of dogs following an abrupt diet change. Methods: Twelve healthy adult English pointer dogs (6.38 ± 2.75 yr) were used in a replicated 3 × 3 Latin square design to test the following treatments: (1) placebo (control; 250 mg maltodextrin/d); (2) live B. pumilus [5 × 10⁹ colony-forming units (CFU)/d]; and (3) L. paracasei postbiotic (100 mg; derived from 2 × 10⁹ CFU/d). Each period lasted 42 days, with the diet change occurring on day 28. Fecal samples were scored and analyzed for pH, dry matter content, and microbiota before and 2, 6, 10, and 14 days after the diet change. Results: The abrupt diet change increased (p < 0.01) fecal pH, increased (p < 0.01) the dysbiosis index, decreased (p < 0.0001) fecal dry matter, and led to a large shift in the fecal microbiota community. Fecal scores were lower (p < 0.05) in the B. pumilus group. B. pumilus reduced (p < 0.05) the relative abundance of fecal Prevotella and Muribaculaceae, while both treatments (B. pumilus; L. paracasei) increased (p < 0.05) the relative abundance of fecal Holdemanella. Conclusions: These results suggest that an abrupt diet change leads to large shifts in fecal microbiota and modified fecal characteristics. The supplementation with a B. pumilus probiotic and a L. paracasei postbiotic slightly altered the relative abundance of a few microbial taxa but was unable to attenuate most responses.