Some strains of bifidobacteria are effective in inhibiting LPS-induced inflammation and thus might be appropriate candidates for probiotic intervention in chronic intestinal inflammation.

Adhesion and anti-inflammatory properties of eight strains of bifidobacteria were tested using the intestinal epithelial cell lines Caco-2, T84, and HT29. Two strains were selected for further assessment of their antiinflammatory capacity in two murine models of colitis. In vivo results confirmed the high anti-inflammatory capacity of a Bifidobacterium bifidum strain.Bifidobacteria are an important group of the intestinal microbiota (21). Several beneficial health effects have been claimed to be based on the presence of bifidobacteria in the colon (reviewed in reference 16), and thus, they become increasingly interesting for probiotic applications in pharmaceutical and dairy products. A promising application is their use in probiotic intervention in inflammatory bowel disease (IBD). Probiotics containing bifidobacteria have been shown to be effective in reducing the severity of inflammation in several rodent models of IBD and in patients with IBD (3,[6][7][8][9]12,19). Several studies have reported an upregulation of the receptors for bacterial lipopolysaccharide (LPS), CD14, and TLR4 in the intestinal epithelium in murine models of IBD and in patients with IBD (4, 13, 15), suggesting a contribution of abnormal LPS stimulation to chronic intestinal inflammation. In a previous study, we were able to show that different strains of bifidobacteria are able to inhibit LPS-induced inflammatory events in intestinal epithelial cells (IECs) (18). Besides the manufacturing criteria, shelf life and gut transit, two main characteristics are crucial for selecting potential probiotic strains: (i) the desired probiotic property, in the case of IBD, an anti-inflammatory effect, and (ii) high adhesion to the intestinal mucosa (reviewed in reference 10).Adhesion to IEC lines. Here, we present our data from an in vitro analysis of eight strains of bifidobacteria covering the major species isolated from human fecal samples. All of the strains were tested for adhesion and anti-inflammatory effects using Caco-2, T84, and HT-29 IECs. For adhesion experiments, Caco-2, T84, and HT-29 cells were grown in 24-well tissue culture plates as described previously (17,18). Bifidobacterium adolescentis NCC251, B. lactis NCC362, B. longum NCC2705, B. bifidum NCC189, S16, and S17, B. longum/infantis E18, and B. breve MB226 (all described previously [18]) were grown to stationary phase at 37°C in MRS medium supplemented with 0.5 g cysteine/liter (MRSC) in anaerobic jars using Anaerocult A (Merck). Bacteria were washed three times with phosphate-buffered saline (PBS) and resuspended at 1 ϫ 10 8 CFU/ml RPMI medium (Gibco) supplemented with 1% nonessential amino acids (Gibco). One-milliliter aliquots were incubated with the IECs, i.e., a bacterium-to-cell ratio of 100:1, for 1 h. After three washings with PBS to remove nonadherent bacteria, IEC monolayers were lysed and bacterial adhesion was quantified in serial dilutions of the lysates by plate counts on MRSC agar. Adhesion was expressed as percent adherent bacteria relative to the initially added C...

No abstract

Specific strains of probiotic, have been identified as beneficial to influence the composition and/or metabolic activity of the endogenous microbiota and some of these strains have been also shown to inhibit the growth of a wide range of enteropathogens. The first aim of using probiotics has been to improve the composition of the intestinal microbiota from a potentially harmful composition towards a composition that would be beneficial to the host.Beyond their capacity to influence positively the composition of the intestinal microbiota, several lines of evidence suggest that some probiotic bacteria can modulate the immune system both at the local and systemic levels thereby improving immune defense mechanisms and/or downregulate immune disorders such as allergies or intestinal inflammation.Skin reflects the general health status and aging. Different human trials widely suggest that probiotic supplementation might be useful in the management of atopic dermatitis. Based on these properties it appears that, beyond the gut, probiotics might exert their benefits at the skin level.In a randomized double blind placebo-controlled clinical trial, we investigated whether the probiotic bacteria Lactobacillus johnsonii NCC 533 (La1) could modulate the cutaneous immune homeostasis altered by solar-simulated UV exposure in humans. After, UV exposure to twice 1.5 MED, we demonstrated that La1 intake facilitated an earlier recovery of Epidermal cells allostimulatory function. Thus, this clinical data strengthen the assumption that certain probiotics can contribute to modulate skin immune system leading to the preservation of the skin homeostasis. Altogether the data affords the possibility of designing new strategies based on a nutritional approach for the prevention of UV-induced damaging effects.

No abstract

No abstract