Meta-analysis of randomized controlled trials of the effects of synbiotics, probiotics, or prebiotics in controlling glucose homeostasis in non-alcoholic fatty liver disease patients.

Background: Probiotics, prebiotics, and synbiotics have been suggested as a possible therapy for non-alcoholic fatty liver disease (NAFLD). However, their efficacy in improving blood glucose levels in NAFLD patients remains uncertain. Objective: The aim of this study was to assess the effects of supplementation with probiotics, prebiotics, or synbiotics on fasting blood glucose (FBG) levels in NAFLD patients. Methods: We searched PubMed, Web of Science, and Google Scholar for relevant trials published up to March 2024. Out of 3369 identified studies, 24 randomized controlled trials (RCTs) were included. Results: Probiotic, prebiotic, or synbiotic supplementation substantially reduced FBG (n = 23; standard mean difference (SMD) = -0.17; 95% confidence interval (CI): -0.30, -0.03; P = 0.02), fasting insulin levels (n = 12; SMD = -0.28; 95% CI: -0.49, -0.07; P = 0.01), and homeostatic model assessment for insulin resistance (HOMA-IR; n = 14; SMD = -0.28; 95% CI: -0.47, -0.09; P = 0.004). However, glycosylated hemoglobin (HbA1c; n = 3; SMD = -0.17; 95% CI: -0.48, 0.13; P = 0.27) was not significantly affected. The FBG-decreasing effect diminished as the body mass index (BMI) of volunteers increased in the baseline. Additionally, the number of probiotic strains and geographic region were shown to significantly affect FBG levels. Conclusion: This meta-analysis indicates that supplementation with probiotics, prebiotics, or synbiotics may aid in controlling glucose homeostasis in patients with NAFLD.

Effect of probiotic Bacillus cereus DM423 on the flavor formation of fermented sausage.

Insufficient protein and fat hydrolysis capacity of lactic acid bacteria (LAB) limit the flavor formation of fermented sausage. Bacillus is known for its substantial expression of proteases and lipases. However, its application in meat fermentation remains underexplored. In this study, a strain of probiotic Bacillus cereus (B. cereus DM423) was employed as a co-starter to improve the quality of Lactiplantibacillus plantarum (L. plantarum HH-LP56) fermented sausage. The addition of DM423 did not interfere with regular fermentation, but it significantly improved the flavor, as measured by electronic tongue and electronic nose. Further analyses using SDS-PAGE and thin-layer chromatography observed enhanced hydrolysis of protein and fat in sausages in which DM423 was involved in fermentation. GC-IMS identified DM423 mediated upregulation of various flavor compounds, including esters, ketones, furans, and branched-chain fatty acids. In addition, genomic de novo sequencing revealed that DM423 carried an abundance of genes associated with proteolysis, lipolysis, and the production of flavor substances, whereas HH-LP56 lacked these genes. Overall, this study finds that B. cereus DM423 can promote flavor formation in fermented sausages. It may illuminate a promising direction for the development of sausage co-starters from a wider microbial pool.