a1 Nestlé Research Center, 1000 Lausanne 26, Switzerland
a2 Department of Physiology of Nutrition, Hohenheim University, 70599, Stuttgart, Germany
A study was conducted in healthy elderly living independently in senior housing to assess the impact of a probiotic yoghurt supplement on small intestinal bacterial overgrowth. Twenty-three participants with positive and thirteen participants with negative hydrogen breath test were studied before and after a period of 4 weeks of probiotic yoghurt administration. Intestinal permeability, plasma endotoxin levels, phagocytic activity of leucocytes, cytokine production by monocytes and free radical response of neutrophils were determined. Intestinal permeability was similar for the two groups and was unaffected by probiotic treatment. Both plasma endotoxin levels and the basal phagocytic activity of leucocytes decreased after yoghurt intake in the two groups. Exposure of monocytes and neutrophils ex vivo led to an increased cytokine response and free radical response, respectively. The normalisation of the various cytokine responses was more apparent in the group with positive breath test. In addition, the plasma levels of lipoplysaccharide binding protein and soluble CD14, lipoplysaccharide pattern recognition receptors and surrogate markers of lipoplysaccharide permeability were diminished by the end of the study. In conclusion, probiotic administration in the elderly normalises the response to endotoxin, and modulates activation markers in blood phagocytes, and therefore may help reduce low-grade chronic inflammation.
(Received February 08 2008)
(Revised June 06 2008)
(Accepted June 07 2008)
(Online publication September 25 2008)
Abbreviations: LBP, lipopolysaccharide binding protein; LPS, lipopolysaccharide; ppm, parts per million; sCD14, soluble CD14; SIBO, small-intestinal bacterial overgrowth; SNH, subjects with negative breath tests; SPH, subjects with positive breath test