North Carolina State University researchers have found that different probiotic strains can have varying effects on gut microbiome recovery after antibiotic treatment. Their study in a mouse model suggests that some probiotics may speed up recovery, while others could delay it. This finding highlights the need for more research to understand how specific probiotic strains affect the gut.
Probiotics are often used post-antibiotics to prevent diarrheal diseases caused by Clostridioides difficile (C. diff). However, the effect of individual probiotic strains on gut bacteria is not well understood.
“Colonization resistance or the ability to prevent colonization of pathogens is a function of a healthy microbiota,” said Casey Theriot, professor of infectious disease at NC State and co-corresponding author of the research. “This study looked at how long it took resistance against C. diff colonization to return after antibiotics and the impact of two of the most commonly used commercial strains of Lactobacillus probiotic on that return.”
The study examined three groups of mice treated with cefoperazone, an antibiotic. One group received no probiotics, another received L. acidophilus, and the third received L. gasseri. All groups were exposed to C. diff weekly for four weeks.
Results showed that mice without probiotics had decreased bacterial load and resistance to C. diff by week four post-antibiotics. The L. acidophilus group saw increased bacterial load in weeks two and three, whereas L.gasseri-treated mice had no detectable C.diff after two weeks.
L.gasseri did not remain in the gut but contributed to antimicrobial peptide production and promoted Muribaculaceae growth—a potentially beneficial bacteria.
“We have always known that it’s important to understand the strain-specific impact of probiotic strains,” said Rodolphe Barrangou, Todd R.Klaenhammer Distinguished Professor at NC State and co-corresponding author.“Depending on…the condition…you will have different effects.”
“What’s interesting is…probiotics can have transient or indirect effects…” Barrangou added.
“This is the only study out there that is functionally testing resistance in the microbiome,” Theriot noted.“Although this work is in a mouse model…it shows…not only can they have effects weeks after they’ve left…they can prolong or complicate recovery.”
The research appears in mBio supported by NIH grants through UNC Center for Gastrointestinal Biology and Disease (CGIBD) and NC State’s Molecular Biotechnology Training Program.Other contributors include Matthew Foley et al.
