Pushback on Probiotics

I had not paid much attention to a study last year (Lancet 2013; 382: 1249-57) titled, “Lactobacilli and bifidobacteria in the prevention of antibiotic-associated diarrhea and Clostridium difficile diarrhea in older patients (PLACIDE): a randomized, double-blind, placebo-controlled, multcentre trial.”

A useful review (Gastroenterol 2014; 146: 1822-23) of this study provides some useful insight into the use of probiotics.  The authors state that “in the last decade, medical and non medical professionals have endorsed the use of probiotics as a means of preventing AAD through a dogma that adding ‘good bacteria’ will prevent dysbiosis caused by ‘bad bacteria.'”  They note that several meta-analysis have supported a positive benefit for probiotics in this setting; yet, the “results merit cautious interpretation owing to a high risk of bias and notable heterogeneity of included studies.”

The PLACIDE study overcomes many of the previous limitations in this well-designed study design which enrolled a large cohort of 2,981 patients (≥65 years old).  The probiotics used in this trial were lactobacillus acidophilus along with bidodbacterium bifidum and lactis.  Ultimately, “patients receiving probiotics were as likely to develop AAD as patients in the placebo arm (relative risk 1.04).”  The rate of C difficile infection was ~1% and lower than expected.

While this study did not demonstrate any benefit from probiotics, there was no significant harm identified from probiotics; though, patients receiving probiotics were more likely to develop flatus and bloating in comparison to placebo.

Take-home message: “This study now also points away from probiotics being of benefit…probiotics use will not diminish as a result of this trial.  Parties will, argue rightly or wrongly, that the wrong strains were chosen…However, what the PLACIDE trial does point is that there is no clear evidence for use of probiotics in this setting until high-quality RCTs are conducted.”

Another probiotic reference:

JAMA Pediatr 2014; 168: 228-33.  This randomized double-blind, controlled trial conducted in 9 neonatal units in Italy compared L reuteri DSM 17938 to placebo for prevention of colic.  Mean duration of daily crying was 38 min in probiotic group compared with 71 min in placebo-treated patients, though these measures were with a nonvalidated diary.  Conclusions of authors: “prophylactic use of L reuteri DSM 17938 during the first 3 months of life reduced the magnitude of crying and functional gastrointestinal disorders.”

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