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Microbial interference between indigenous yeast and lactobacilli in the rodent stomach
Abstract:
Indigenous yeasts grow in layers in the mucus on the secreting epithelium of the stomachs of some strains of rats and mice raised under conventional conditions. Likewise, indigenous lactobacilli appear in layers on the nonsecreting epithelium of the stomachs of rats and mice. The two microbial layers can coexist in the same animals. When I gave such rodents penicillin solution in the place of drinking water, the lactobacilli disappeared, and the yeast from the secreting epithelium colonized the nonsecreting epithelium within 24 hr. The yeast remained in layers on the nonsecreting, as well as the secreting epithelium, as long as penicillin was administered. There is no inflammatory reaction or any sign that the yeast invaded below the keratin layer. When the penicillin treatment was discontinued, within 5 to 8 days the indigenous lactobacilli again colonized the nonsecreting epithelium. Concomitantly the yeast was displaced from the keratinized tissue and once more could be found only on the secreting epithelium. Only 2 days were required, however, for the bacteria to recolonize the keratin layer and displace the yeast when the mice were given indigenous lactobacilli in pure culture immediately after the penicillin treatment was discontinued. The lactobacilli must displace the yeast from the nonsecreting epithelium by interfering either with multiplication of the yeast on the tissue or with attachment of the yeast cells to the keratin layer. This interference must proceed continuously during normal life since the yeast never populates the nonsecreting epithelium as long as the lactobacilli are present.
Insights
Indigenous lactobacilli prevent yeast colonization in rodent stomachs. Antibiotic treatment allows yeast to overgrow, but lactobacilli quickly re-establish, displacing the yeast and maintaining stomach microbial balance.
Area of Science:
- Microbiology
- Gastroenterology
- Microbial Ecology
Background:
- Indigenous yeasts and lactobacilli inhabit distinct epithelial layers in rodent stomachs.
- These microbial communities coexist under normal conditions.
Purpose of the Study:
- To investigate the role of indigenous lactobacilli in regulating yeast colonization in rodent stomachs.
- To understand the dynamics of microbial interactions following antibiotic-induced disruption.
Main Methods:
- Administration of penicillin to disrupt indigenous microbiota.
- Observation of yeast and lactobacilli distribution on gastric epithelium.
- Reintroduction of lactobacilli after antibiotic treatment.
Main Results:
- Penicillin treatment led to lactobacilli disappearance and yeast colonization of non-secreting epithelium.
- Yeast remained on non-secreting epithelium during antibiotic administration without inflammation.
- Discontinuation of penicillin allowed lactobacilli to recolonize and displace yeast within 5-8 days.
- Pure culture lactobacilli reintroduction rapidly displaced yeast within 2 days.
Conclusions:
- Indigenous lactobacilli actively prevent yeast from colonizing the non-secreting gastric epithelium.
- Lactobacilli interfere with yeast multiplication or attachment to the keratin layer.
- This competitive exclusion by lactobacilli is crucial for maintaining normal gastric microbial homeostasis.