Researchers investigate effects of probiotics

WASHINGTON — Probiotics were the topic of four studies presented at the American College of Gastroenterology’s Annual Scientific Meeting and Postgraduate Course here.

In the first meta-analysis of probiotics as a treatment for antibiotic-associated diarrhea and Clostridium difficile-associated diarrhea,researchers from the Maimonides Medical Center in New York found that probiotic prophylaxis reduced the odds ratio of developing antibiotic-associated diarrhea by approximately 60%.

“These findings suggest that all patients who are at high risk for these infections demonstrated by recent antibiotic usage, old age, recent hospitalization, low albumin, and immunosuppression should be considered for probiotic therapy,” Rabin Rahmani, MD, principal investigator of the study, said.

In a meta-analysis of 28 randomized, controlled trials including 3,338 patients, researchers from Beth Israel Deaconess Medical Center in Boston found a significant preventive effect of probiotic use for antibiotic-associated diarrhea across demographics and antibiotic administered.

“The preventive effect of probiotics is also apparent during combined antibiotic treatment for H.pylori eradication,” Elizabeth Videlock, MD, one of the researchers, said.

Researchers from the University of North Carolina at Chapel Hill were unable to demonstrate a statistically significant improvement in abdominal discomfort and bloating in a non-patient population taking Bifidobacterium infantis 35624, a probiotic previously found effective in IBS patients.

Yehuda Ringel, MD, who presented the findings, attributed the result in part to the high placebo response and a possible floor effect, with severity of symptoms too low to measure improvement.

“Our secondary finding of significantly more bloating-free days in the B. infantis 35624 group needs further studies, particularly in the non-patient, healthy population,” Ringel said.

A double-blind, placebo-controlled study by researchers at the Alimentary Pharmabiotic Centre at University College Cork and Alimentary Health Ltd. in Cork, Ireland, examined the influence of B. infantis on systemic pro-inflammatory biomarkers in patients with psoriasis, ulcerative colitis or chronic fatigue syndrome.

“The human immunological response to B. infantis further supports the hypothesis that manipulation of the microbiota with specific therapeutic microbes can have a significant effect on host inflammatory processes,” Eamonn M.M. Quigley, MD, FACG, who presented the study, said.

Study results showed that plasma levels of the anti-inflammatory cytokine IL-10 were significantly increased for 8 weeks in healthy volunteers and patients with psoriasis. Plasma levels of the pro-inflammatory cytokines TNF-alpha and IL-6 were significantly reduced in all patient groups that received B. infantis. C-reactive protein levels were also significantly reduced in patients with psoriasis, ulcerative colitis and chronic fatigue.