Dynamic Duo: Antibiotics and Probiotics

Post on Dec 10, 2012 by Jennifer Huber from QUEST Northern California

Antibiotics work by killing bacteria or by stopping bacteria from multiplying. Each type of antibiotics affects different bacteria in different ways, although broad-spectrum antibiotics are used to treat a wide range of infections. Antibiotics quickly make you feel better because the drug kills the majority of the targeted bacteria very quickly.

However antibiotics also kill beneficial bacteria and induce negative side effects — most commonly diarrhea, upset stomach, and vaginal yeast infection. For instance, antibiotics cause about one out of three people to get diarrhea by disrupting the balance of the intestinal flora, a collection of bacteria and other microorganisms in the digestive tract. This can result in an overgrowth of the Clostridium difficile bacteria that causes diarrhea. Similarly, antibiotics can disrupt the vaginal flora and cause an overgrowth of Candidayeasts to cause a yeast infection.

Probiotics are live bacteria, yeasts and other microbes intended to maintain or restore the supply of beneficial bacteria in the body, particularly the stomach and intestines. Probiotics are found naturally in certain foods, including yogurt, aged cheeses, kefir, miso, tempeh, and fermented cabbage. Dietary supplements are another common source of probiotics.

Although probiotics have been widely promoted as a way to keep your body in balance, scientific evidence for these claims have been weakened by the small size of most research studies. However, the use of probiotics to reduce antibiotic-induced side effects is now becoming more widely accepted by the medical profession.

In a recent study  published in the Journal of the American Medical Association supports taking probiotics with antibiotics. A team of researchers from southern California combined and analyzed the results of 63 randomized controlled trials of probiotics for the prevention or treatment of antibiotic-associated diarrhea. The 11811 men and women included in this large combined study took a placebo or probiotics supplement along with their antibiotics. The people who took the probiotics were 42% less likely to develop diarrhea than those taking the placebo. This pooled evidence strongly suggests that probiotics can help populations of beneficial bacteria recover and more quickly restore balance in the intestines.

However, further research is needed to determine which probiotics are the most effective at preventing and treating antibiotic-associated side effects, as well as determine the optimal dose of the probiotics. Research is also needed to identify which antibiotics are most likely to induce adverse effects. Hopefully these further studies are underway.

Of course it is also important to limit your use of antibiotics, using them only for bacterial infections when necessary. Common cold and flu viruses don’t respond to antibiotics anyway.

Science

Antibiotic treatment for Clostridium difficile-associated diarrhea in adults

Antibiotic treatment for Clostridium difficile-associated diarrhea in adults

Cochrane Database Syst Rev. 2007 Jul

Nelson R.
Northern General Hospital, Department of General Surgery, Herries Road, Sheffield, Yorkshire, UK, S5 7AU. altohorn@btinternet.com

BACKGROUND: Clostridium difficile (C. difficile) is recognized as a frequent cause of antibiotic-associated diarrhea and colitis.

OBJECTIVES: The aim of this review is to establish the efficacy of antibiotic therapy for C. difficile-associated diarrhea (CDAD), to identify the most effective antibiotic treatment for CDAD in adults and to determine the need for stopping the causative antibiotic during therapy.

SEARCH STRATEGY: MEDLINE (1966 to 2006), EMBASE (1980 to 2006), Cochrane Central Database of Controlled Trials and the Cochrane IBD Review Group Specialized Trials Register were searched using the following search terms: "pseudomembranous colitis and randomized trial"; "Clostridium difficile and randomized trial"; "antibiotic associated diarrhea and randomized trial".

SELECTION CRITERIA: Only randomized, controlled trials assessing antibiotic treatment for CDAD were included in the review. Probiotic trials are excluded. The following outcomes were sought: initial resolution of diarrhea; initial conversion of stool to C. difficile cytotoxin and/or stool culture negative; recurrence of diarrhea; recurrence of fecal C. difficile cytotoxin and/or positive stool culture; patient response to cessation of prior antibiotic therapy; sepsis; emergent surgery: fecal diversion or colectomy; and death.

DATA COLLECTION AND ANALYSIS: Data were analyzed using the MetaView statistical package in Review Manager. For dichotomous outcomes, relative risks (RR) and 95% confidence intervals (CI) were derived from each study. When appropriate, the results of included studies were combined for each outcome. For dichotomous outcomes, pooled RR and 95% CI were calculated using a fixed effect model, except where significant heterogeneity was detected, at which time the random effects model was used. Data heterogeneity was calculated using MetaView.

MAIN RESULTS: Twelve studies (total of 1157 participants) involving patients with diarrhea who recently received antibiotics for an infection other than C. difficile were included. The definition of diarrhea ranged from at least two loose stools per day with an associated symptom such as rectal temperature > 38 (o)C, to at least six loose stools in 36 hours. Eight different antibiotics were investigated: vancomycin, metronidazole, fusidic acid, nitazoxanide, teicoplanin, rifampin, rifaximin and bacitracin. In paired comparisons, no single antibiotic was clearly superior to others, though teicoplanin, an antibiotic of limited availability and great cost, showed in some outcomes significant benefit over vancomycin and fusidic acid, and a trend towards benefit compared to metronidazole. Only one placebo controlled trial was done and no conclusions can be drawn from it due to small size and classification error. Only one study investigated synergistic antibiotic combination, metronidazole and rifampin, and there was no advantage to the drug combination.

AUTHORS' CONCLUSIONS: Current evidence leads to uncertainty whether mild CDAD needs to be treated. Patients with mild CDAD may resolve their symptoms as quickly without treatment. The only placebo-controlled study shows vancomycin's superior efficacy. However, this result should be treated with caution due to the small number of patients enrolled and the poor methodological quality of the trial. The Johnson study of asymptomatic carriers also shows that placebo is better than vancomycin or metronidazole for eliminating C. difficile in stool during follow-up. If one does decide to treat, then two goals of therapy need to be kept in mind: improvement of the patient's clinical condition and prevention of spread of C. difficile infection to other patients. Given these two considerations, one should choose the antibiotic that brings both symptomatic cure and bacteriologic cure.

In this regard, teicoplanin appears to be the best choice because the available evidence suggests that it is better than vancomycin for bacteriologic cure and has borderline superior effectiveness in terms of symptomatic cure. Teicoplanin is not readily available in the United States, which must be taken into account when making treatment decisions in that country.

Plain language summary

Antibiotic therapy for Clostridium difficile-associated diarrhea (CDAD) needs further investigation.Diarrhea may be a side effect of many commonly used antibiotics, and this is in some cases due to overgrowth of a bacterium called Clostridium difficile (C. difficile) in the colon after other bacteria have been killed. The seriousness of C. difficile-associated diarrhea can range from being a nuisance to a life threatening or even fatal disease. The treatment of CDAD is usually cessation of the initiating antibiotic and immediate administration of a new antibiotic. However each of these three strategies, cessation of the original antibiotic, immediate retreatment, and the choice of a new antibiotic are poorly supported by currently available evidence. The antibiotic that is most tested, vancomycin, is the one most prone to serious side effects. Seven other antibiotics are included in this review and within the limitations of the included studies, they each seem to be as effective as vancomycin.

The Cochrane Library