Acids produced by lactobacilli inhibit the growth of commensal Lachnospiraceae and S24-7 bacteria

Abstract

The Lactobacillaceae are an intensively studied family of bacteria widely used in fermented food and probiotics, and many are native to the gut and vaginal microbiota of humans and other animals. Various studies have shown that specific Lactobacillaceae species produce metabolites that can inhibit the colonization of fungal and bacterial pathogens, but less is known about how Lactobacillaceae affect individual bacterial species in the endogenous animal microbiota. Here, we show that numerous Lactobacillaceae species inhibit the growth of the Lachnospiraceae family and the S24-7 group, two dominant clades of bacteria within the gut. We demonstrate that inhibitory activity is a property common to homofermentative Lactobacillaceae species, but not to species that use heterofermentative metabolism. We observe that homofermentative Lactobacillaceae species robustly acidify their environment, and that acidification alone is sufficient to inhibit growth of Lachnospiraceae and S24-7 growth, but not related species from the Clostridiales or Bacteroidales orders. This study represents one of the first in-depth explorations of the dynamic between Lactobacillaceae species and commensal intestinal bacteria, and contributes valuable insight toward deconvoluting their interactions within the gut microbial ecosystem.

The Effect of Hydrolyzed and Fermented Arabinoxylan-Oligo Saccharides (AXOS) Intake on the Middle-Term Gut Microbiome Modulation and Its Metabolic Answer

“…The enhanced relative abundance of Lactobacillaceae resulting after the intake of fermented and hydrolyzed formulations can be considered a beneficial effect. The mechanisms by which several species belonging to Lactobacillaceae family prevent the growth of pathogenic bacteria or fungi through nutrient or niche competition and/or the production of antimicrobial compounds has been largely demonstrated and aids the restoration of the gut microbiota after perturbation with antibiotics [ 26 ]. On the other hand, several yeasts belonging to Candida , which increased the relative abundance after feeding with fermented and hydrolyzed formulations, are considered true symbionts of the human gut.…”

Sodium glucose co-transporter 2 (SGLT2) inhibition via dapagliflozin improves diabetic kidney disease (DKD) over time associatied with increasing effect on the gut microbiota in db/db mice

“…Notably, the abundance of Lactobacillus seemed to be always negatively associated with the quantity of norank_f:Muribaculaceae in the DKD model group and DAPA intervention group. Thinking about the association between Firmicutes and Bacteroides at 18 weeks and 22 weeks, by searching PubMed online articles, one recent report in 2022 concluded that acids produced by lactobacilli inhibited the growth of commensal Lachnospiraceae and Muribaculaceae ( 46 ). Besides, similar to the microbial alteration pattern of negative correlations in our study, studies showed that treatment with intervention hugely reversed the increased F/B ratio, which is the hallmark of dysbiosis, accompanied by a striking downregulation of Lactobacillus belonging to Firmicutes ( 47 , 48 ).…”

Ulinastatin ameliorates acute pancreatitis and associated intestinal and pulmonary injury by inhibiting NLRP3 inflammatory vesicles and affecting intestinal flora composition and metabolic pathways in rat

“…There is evidence that the abundance of Lachnospiraceae and S24−7 is in uenced by the pH of the intestine, which decreases and the growth of both is inhibited [41]. The acid produced by Lactobacillaceae is one of the reasons for the lowering of the intestinal pH [41]. From our results, ulinastatin affected the decrease in the abundance of Lachnospiraceae and S24−7 in the intestine of AP rats, suggesting that ulinastatin may have altered the pH of the mouse intestine.…”

“…S24−7 is also a bacterium that accounts for approximately 20% of the mouse intestine [40]. There is evidence that the abundance of Lachnospiraceae and S24−7 is in uenced by the pH of the intestine, which decreases and the growth of both is inhibited [41]. The acid produced by Lactobacillaceae is one of the reasons for the lowering of the intestinal pH [41].…”