Clinical trial for probiotics in irritable bowel syndrome fails to show efficacy

Irritable bowel syndrome is the most common functional gastrointestinal disorder, affecting about 10-15% of people in the United States alone, according to the International Foundation for Functional Gastrointestinal Disorders website. Fortunately, as described by the IFFGD, IBS is a functional disorder, meaning that while it does affect quality of life, it does not affect life expectancy. Probiotics have been studied as treatment for IBS because, as we’ve seen in many other examples of probiotic use, it is safe and rarely has any negative effects on the consumer. Some trials have shown that probiotics help relieve the symptoms of IBS; however the conclusions are controversial due to study structure and participant numbers. For this reason, scientists in Seoul, South Korea recently published a study in the Journal of Clinical Biochemistry and Nutrition, which studied the effects of a multi-species probiotic mixture on IBS symptoms using a double-blind study with a large number of participants.

Eighty-one patients participated in the 4-week-long double-blind study, with 42 people receiving a multi-species probiotic (containing Lactobacilli, Bifidobacteria, and Streptococci) and 38 people receiving a placebo. Baseline fecal samples were collected before probiotic/placebo consumption, revealing no significant difference between the two groups of participants. After consumption, the probiotic group showed a significant increase in concentrations of the probiotic bacterial strains in fecal samples, but not significant increase of levels of Bacteroidetes and Firmicutes.

In terms of symptom relief, while the probiotic group reported a greater percentage of relief, it was not significantly greater than the placebo group. This could be a classic case of the placebo effect, which is a phenomenon in which a sham treatment can actually improve symptoms because the person receiving the placebo believes it will help them. The results of this study are not concrete because there was no significant difference in symptom improvement; however there were significant increases in probiotic strains in fecal samples of the probiotic group. This study could be a step in the right direction toward relieving IBS symptoms.

Randomized clinical trial shows probiotic may not be an effective treatment for colic

Many families have experienced colicky infants who have excessive and inconsolable crying.  The cause of this behavior is largely unknown, however it is beginning to be linked to a variety of diseases, including allergies and gastrointestinal disorders.  Many remedies have been suggested to help assuage these infants, including probiotic therapies, but thus far the evidence of their efficacy is unknown.  Researchers in Finland put one of the probiotic therapies, using Lactobacillus rhamnosus GG (LGG), to the test and conducted a double blind randomized clinical trial to discover whether it decreased colic.  They published their results last week in Nature Pediatric Research. 

The scientists studied 30 colicky infants in the study, who were split evenly into a probiotic group and a control group.  The mothers of the probiotic group orally administered LGG to their children once a day for 28 days, while the mothers of the control group orally administered a placebo.  During this time the mothers kept diaries of how long the child cried, as well as collected stool samples for microbiome testing.  The results showed that the probiotics did not alter the amount of crying for each infant when compared to the placebo group.  In addition there was no statistical difference in the microbiome’s of both groups.

Unfortunately for the families of colicky infants, this study did not show that LGG was an effective colic therapy.  There are other studies that conflict with this one though, so perhaps different types of bacteria, or larger doses could improve efficacy.  The relationship between the microbiome and colic is unclear, however, given the recent advances in gut-brain axis research, we would not be surprised if the two are connected.

Antibiotic resistant bacteria at UCLA and how the microbiome can prevent similar infections

Endoscopes (the instrument that resulted in infections at UCLA) in sterilization equipment

Over the past few weeks at Ronald Reagan UCLA Medical Center in Los Angeles, California, 179 patients were exposed to Carbapenem-resistant enterobacteriaceae or CRE, resulting in seven patients being infected and two deaths.  This is a lethal bacterium that is very resistant to antibiotics and has resulted in significant discussion in the press. Hospital patients with compromised immune systems are susceptible to infections passed on from other patients and hospital equipment and in the current case of CRE at UCLA, a contaminated endoscope.

Another prominent cause of infection is the bacteria enterococci, specifically vancomycin-resistant enterococci (VRE), which, as the name states, are resistant to the antibiotic vancomycin. In healthy individuals, the bacteria are not a threat and are usually killed by the immune system. In cancer patients, the elderly, transplant recipients, and other patients on antibiotics, the weakened immune system and microbiome colonization cannot fight the colonization of VRE in the gut. The result is an infection of the intestines, and possibly of the urinary tract, blood stream, and heart.

In an article published in FEMS Microbiology Letters in early February, the authors summarize research that is being done to overcome the issue of VRE infection. Infection by enterococci often occurs in patients who have taken antibiotics that deplete beneficial bacteria in the gut. One possible fix for this problem could be the administration of probiotics, live microorganisms that provide a health benefit. Unfortunately, limited research has been done in this area. In one inconclusive study, Lactobacillus rhamnosus appeared to eliminate or at least decrease the presence of VRE in the gut. Other studies suggest that it is easier to prevent infection of, rather than eradicate already present VRE.  

Another area of investigation is the use of commensal bacteria to prevent infection, or the administration of normal gut-colonizing bacteria. A popular topic in microbiome research, and one that often, and recently, appears on our blog is the treatment of infection of Clostridium difficile. One method of treatment that we frequently discuss is fecal microbiota transplant (FMT). The authors of this article suggest the use of FMTs may be able to be applied for the treatment of enterococci infection. 

Many hospital patients get sick from infections passed within the hospital, as their compromised immune systems cannot stave off infection. Hospitals are supposed be a place for getting healthier, yet we know that hospital-acquired infections are a major issue in today’s hospital systems as we have seen over the past few weeks at UCLA. New strategies for overcoming these issues are being pursued and are very important for the prevention of deaths resulting in bacterial infections passed within hospitals.