Noninvasive fecal metabolic profiling for the evaluation of characteristics of thermostable lactic acid bacteria, Weizmannia coagulans SANK70258, for broiler chickens

Weizmannia coagulans SANK70258 is a spore-forming thermostable lactic acid bacterium and an effective probiotic for the growth of livestock animals, but its growth-promoting mechanism remains unclear. Here, the composition of fecal metabolites in broilers continuously administered with W. coagulans SANK70258 was assessed under a regular program with antibiotics, which was transiently given for 6 days after birth. Oral administration of W. coagulans to broiler chicks tended to increase the average daily gain of body weights thereafter. The composition of fecal metabolites in the early chick stage (Day 10 after birth) was dramatically altered by the continuous exposure. The levels of short-chain fatty acids (SCFAs) propionate and butyrate markedly increased, while those of acetate, one of the SCFAs, and lactate were reduced. Simultaneously, arabitol, fructose, mannitol, and erythritol, which are carbohydrates as substrates for gut microbes to produce SCFAs, also increased along with altered correlation. Correlation network analyses classified the modularity clusters (|r| > 0.7) among carbohydrates, SCFAs, lactate, amino acids, and the other metabolites under the two conditions. The characteristic diversities by the exposure were visualized beyond the perspective associated with differences in metabolite concentrations. Further, enrichment pathway analyses showed that metabolic composition related to biosynthesis and/or metabolism for SCFAs, amino acids, and energy were activated. Thus, these observations suggest that W. coagulans SANK70258 dramatically modulates the gut metabolism of the broiler chicks, and the metabolomics profiles during the early chick stages may be associated with growth promotion.