What do peanut butter, pistachios, cantaloupes, and eggs have in common? They have all been recent sources of Salmonella food borne illnesses in humans.
Since we are in the middle of a nationwide outbreak of a Salmonella infection due to contaminated eggs, I thought it would be of interest to discuss the benefits of probiotics against Salmonella infections.
If you are feeling paranoid about what to eat, you may feel safer taking EndoMune after reading this newsletter.
There are a number of reasons why probiotics may prevent or shorten the duration of a bout of infectious diarrhea like Salmonella.
- Secrete bacteriocins (proteins that can kill harmful invading bacteria)
- Produce products like lactic acid and hydrogen peroxide that inhibit infectious bacteria
- Stimulate the intestinal immune system to release antibodies and inflammatory cells to destroy the hostile bacteria
- Carpet the intestinal lining to prevent the harmful bacteria from attaching and invading the intestinal lining cells
With the knowledge that probiotics can have a beneficial effect against infectious bacteria, researchers have done several types of investigations.The following are studies where probiotics have been shown to be helpful:
Acute Infectious Diarrhea
A number of controlled trials(1) have compared probiotics versus placebo when treating children and adults with acute infectious diarrhea, including Salmonella. The general finding was that probiotic could reduce the duration and severity of the illness. The diarrheal illnesses were shortened, on average, 1-2 days in the individuals who were taking a probiotic.
The cause of traveler’s diarrhea is exposure to food and water that has been contaminated with fecal matter due to poor sanitary and public health conditions. The organisms that cause the diarrhea are bacteria, viruses and parasites. Studies have found that bacteria like E. coli, Shigella, Salmonella and Campylobacter account for 80% of the episodes. There have been a number of published controlled trials giving travelers either probiotics or placebos. A review(5) of 12 well done clinical trials found that probiotics were safe and generally effective in preventing traveler’s diarrhea. Compared to the travelers receiving a placebo, the probiotic travelers had about 25-50% fewer bouts of diarrhea.
Several recent research studies have investigated how probiotics inhibit Salmonella. One study(6)incubated either Salmonella alone or the combination of probiotics and Salmonella on cultures of human colon cells. The immune reactions in the intestinal cells that were exposed to the probiotic with the Salmonella were much greater than that seen in the cells in contact with only the Salmonella. The study showed that the probiotics could stimulate the release of protective immune reactions against the Salmonella bacteria.
In another study(7), one group of mice were fed probiotics for seven days before being challenged with Salmonella. The other group did not receive the probiotic. The survival rate was greater and the infection milder in the group receiving the probiotics. Studies of the intestinal fluid found much higher levels of antibodies against the Salmonella bacteria. Again, this would indicate that the probiotics stimulate the intestinal immune system to fight harmful intestinal bacteria.
Take Home Message
Be careful about the eggs you consume and make sure you cook them thoroughly. Avoid the runny eggs like poached eggs or eggs that are served sunny-side up. Eggs Benedict with hollandaise sauce is probably not a good idea, at least for now. You may want to consider a bowl of oatmeal until all the bad eggs are recalled.
If you are still concerned about exposure to Salmonella, consider taking a high quality probiotic like EndoMune.
Eat healthy, exercise and live well!
(1) Guidance for substantiating the evidence for beneficial effects of probiotics: prevention and management of infections by probiotics.Wolvers D, Antoine JM, Myllyluoma E, Schrezenmeir J, Szajewska H, Rijkers GT.J Nutr. 2010 Mar;140(3):
(2) Probiotics have clinical, microbiologic, and immunologic efficacy in acute infectious diarrhea.Chen CC, Kong MS, Lai MW, Chao HC, Chang KW, Chen SY, Huang YC, Chiu CH, Li WC, Lin PY, Chen CJ, Li TY.Pediatr Infect Dis J. 2010 Feb;29(2):135-8.
(3) Clinical evidence for immunomodulatory effects of probiotic bacteria.
Ruemmele FM, Bier D, Marteau P, Rechkemmer G, Bourdet-Sicard R, Walker WA, Goulet O.J Pediatr Gastroenterol Nutr. 2009 Feb;48(2):126-41. Review
(4) Probiotics for treating infectious diarrhoea(Cochrane Review). Reviewers: Allen, Stephen J; Okoko, B; Martinez, Elizabeth G; Gregorio, Germana V; Dans, Leonila F. Review Group: Cochrane Infectious Diseases Group; Cochrane Database of Systematic Reviews; Edited/Substantively amended: 11 November 2008; Edited (no change to conclusions) this issue
(5)McFarland LV: Meta-analysis of probiotics for the prevention of traveler’s diarrhea. Travel Med Infect Dis. 2007;2:97-105
(6) Microbial products from probiotic bacteria inhibit Salmonella enteritidis 857-induced IL-8 synthesis in Caco-2 cells.Malago JJ, Nemeth E, Koninkx JF, Tooten PC, Fajdiga S, van Dijk JE.Folia Microbiol (Praha). 2010 Jul;55(4):401-8. Epub 2010 Aug 3
(7) Anti-infective mechanisms induced by a probiotic Lactobacillus strain against Salmonella enterica serovar Typhimurium infection.de LeBlanc Ade M, Castillo NA, Perdigon G.Int J Food Microbiol. 2010 Apr 15;138(3):223-31. Epub 2010 Feb 1.