Coarse structured feed stimulates members of the genera Lactobacillus and Mitsuokella as well as propionate and butyrate producers in the pig stomach

Pigs in four groups were fed fine non-pelleted (F-NP), fine pelleted (F-P), coarse non-pelleted (C-NP) or coarse pelleted (C-P) diets. DNA fingerprints, T-RFLP, revealed a strong dietary effect on bacterial community structure in the stomachs. Pigs fed the C-NP diet had the highest microbial diversity in stomach and the T-RFLP fingerprints suggested that bacteria tentatively identified as Lactobacillus delbrueckii, L. mucosae, L. reuteri, L. amylovorus/L. sobrius, Mitsuokella multiacida and Megasphera elsdenii were specifically stimulated. Lactobacilli may be responsible for the previously reported increase in stomach lactate levels of pigs fed the C-NP diet [Mikkelsen, L.L., Naughton, P.J., Hedemann, M.S., Jensen, B.B., 2004. Effects of physical properties of feed on microbial ecology and survival of Salmonella enterica serovar Typhimurium in the pig gastrointestinal tract. Appl. Environ. Microbiol. 70, 3485–3492.]. Moreover, earlier observations of butyrate and propionate accumulation in the stomach of pigs fed C-NP diets could be due to stimulation of M. elsdenii and S. ruminantium according to the T-RFLP fingerprints.