The prevalence of diabetes mellitus is increasing worldwide. Lactic acid bacteria have shown efficacy in alleviating diabetes. We studied the remission effect of nine strains of lactic acid bacteria on the symptoms of high-fat diet- and streptozotocin-induced type 2 diabetes and its mechanism in mice. The oral administration of Bifidobacterium adolescentis, B. bifidum or Lactobacillus rhamnosus to mice every day for more than 12 weeks showed that the individual strains could reduce the fasting and postprandial blood sugar levels, improve glucose tolerance and prevent pancreatic damage. However, L. rhamnosus strains showed greater efficacy than Bifidobacterium strains in the regulation of blood lipid levels. The effects of lactic acid bacteria on the recovery of glycolipid metabolism disorder and gut microbiota dysbiosis showed inter- and intraspecific differences. In addition, the strains that exhibited hypoglycaemic effects played a beneficial role in reducing insulin resistance by contributing to the production of short-chain fatty acids and alleviation of inflammation. The ability of lactic acid bacteria to reduce inflammation was found to be closely related to their ability to alleviate diabetes mellitus.

Inflammatory bowel disease (IBD) is a worldwide chronic intestinal inflammatory immune-related disease. In this study, mice with dextran sulfate sodium (DSS)-induced colitis were used to evaluate the effect of Lactobacillus acidophilus on colitis. The results revealed that L. acidophilus CCFM137 and FAHWH11L56 show potential for relieving colitis symptoms, while L. acidophilus FGSYC48L79 did not show a protective effect. Moreover, L. acidophilus NCFM and FAHWH11L56 showed similar effects on various indicators of DSS-induced colitis, increasing the IL-10 and IL-17 in the colon, and modifying the CCL2/CCR2 axis and CCL3/CCR1 axis. For L. acidophilus CCFM137, its effects on colitis were different from the above two strains. Moreover, L. acidophilus FGSYC48L79 had negative effects on colitis by increasing the abundance of harmful bacteria in the gut microbiota and may promote the signaling of chemokines and their receptors. This may be related to its special genome compared to the other strains.