This week on BBS: Heavy metal exposure changes microbiota populations, scientists are getting closer to concluding that probiotics are good for H. pylori treatment, and intestinal bacteria help prime the mucosal immune system.
Not Every Bacteria Likes Heavy Metal
Exposure to heavy metal pollutants is becoming more prominent in today’s society. It is known that heavy metals compromise many vital functions of the body, leading to reduced health. Now that it is known that the intestinal microbiota is important for good health, researchers considered that one link between heavy metals and poor health could be changes in the microflora. To answer this question, researchers examined the intestinal microbiota of mice given oral lead and cadmium for eight weeks. They found that certain changes could be detected, including low numbers of the family Lachnospiraceae and increased numbers of Lactobacillaceae and Erysipelotrichaceacae. These changes may be behind certain heavy metal-related intestinal diseases.
Probiotics for H. Pylori Are Looking Good
Helicobacter pylori, the bacterial pathogen associated with ulcers, are treated with a cocktail of antibiotics in adults and children. However, heavy antibiotic treatment is problematic and can cause other problems like diarrhea. Therefore, a desired strategy is to combine the standard treatment with probiotics to lessen these problems. In a new meta-analysis of studies performed in children, researchers from China sought to find definitive proof that combination therapy works best. Using seven studies with a total of 508 patients, they came to the conclusion that combination therapy may be beneficial at both eliminating H. pylori and preventing diarrhea.
Meeting Microbiota for the Very First Time
To study the effects of different bacteria on the immune system, scientists use mice housed in bacteria free environments. These, “germ-free,” mice were perfect candidates for scientists from the Netherlands to find out what happens when the immune system and the intestinal flora meet for the first time. They found that introduction of normal intestinal flora was first characterized by a temporary outgrowth of several bacteria that induced a mild inflammatory response in the host mice. This process had the benefit of fully maturing the immune system of these mice. This effect was found to be necessary for the healthy adaptation of these mice to hosting intestinal bacteria.
- Breton J, Massart S, Vandamme P, De Brandt E, Pot B, Foligne B. Ecotoxicology inside the gut: impact of heavy metals on the mouse microbiome. BMC Pharmacol Toxicol 2013; 14(1): 62.
- Aidy SE, Derrien M, Aardema R, Hooiveld G, Richards SE, Dane A et al. Transient inflammatory-like state and microbial dysbiosis are pivotal in establishment of mucosal homeostasis during colonisation of germ-free mice. Benef Microbes 2013: 1-11. [Epub ahead of print]
- Li S, Huang XL, Sui JZ, Chen SY, Xie YT, Deng Y et al. Meta-analysis of randomized controlled trials on the efficacy of probiotics in Helicobacter pylori eradication therapy in children. Eur J Pediatr 2013. [Epub ahead of print]