Probiotic without effect against Salmonella

In Sweden around 4,000 people a year are infected with Salmonella bacteria, with around 85 per cent picking up the infection abroad. The acute infection is generally followed by a lengthy period of stomach troubles such as diarrhea, stomach ache, wind and constipation.

"Antibiotics are used in serious cases of Salmonella, but there isn't a good treatment for the acute diarrhea and the more protracted symptoms," says Elisabet Lönnermark, doctor in the Department of Infectious Disease at Sahlgrenska University Hospital and researcher at the Sahlgrenska Academy.

Probiotics are currently being trialled as a treatment for a number of different conditions, but few studies have investigated whether they have any effect on patients with Salmonella.

"We wanted to see whether probiotics, in this case a lactic acid bacterium, could be used to treat diarrhea in patients with Salmonella," says Lönnermark.

The study included 163 Salmonella patients, 90 per cent of whom had picked up the infection abroad. Half were treated with the probiotic lactic acid bacterium, while the other half were given powdered skimmed milk. The outcome was that the group on the probiotic did not have less diarrhea or a shorter period with the Salmonella bacteria in their gut.

"We could see that the men who were treated with the probiotic bacterium were less constipated than those who were given the powdered skimmed milk," says Lönnermark. "Whatever the treatment, the women felt ill to a greater extent and also had diarrhoea for longer than the men, though they got rid of the Salmonella bacteria slightly more quickly."

There is a rising public interest in the role of gut bacteria in our health and how we can affect these bacteria by taking probiotics.

"The bacteria we have in our gut seem to be important for our health, and probiotic bacteria could ease and prevent various symptoms, but it's a matter of finding the right bacterium for the condition you're treating, and perhaps combining several different bacteria," says Lönnermark. "What's more, the effects can differ between women and men."

About Probiotics

Probiotics are living microorganisms, for example different lactic acid bacteria and yeasts, that have a positive impact on our health. The most common forms are lactobacilli and bifido bacteria. Studies have shown that probiotics can sometimes reduce diarrhea caused by viruses or antibiotics, and can also alleviate inflammatory intestinal diseases and ease constipation. Probiotics can be taken as tablets or as yoghurt and fruit drinks with the organisms added.

Thesis: Lactobacilli in the normal microbiota and probiotic effects of Lactobacillus plantarum.