Effects of Lactic Acid Bacteria and Fermented Milks on Eicosanoid Production by Intestinal Epithelial Cells

Graduate Student Literature Review: Potential mechanisms of interaction between bacteria and the reproductive tract of dairy cattle

Although the presence of bacteria has been characterized throughout the reproductive tracts of multiple species, how these bacteria may interact with the host has yet to be described. Previous reviews have described how pathogenic bacteria interact with the reproductive tract to cause infections such as metritis. This review aimed to summarize the knowledge related to pathogenic and nonpathogenic bacteria in various locations of the bovine reproductive tract and the possible mechanisms underlying host-microbe interactions during gametogenesis and early pregnancy. Lactic acid bacteria such as Lactobacillus seem to be beneficial in multiple areas of the reproductive tract: they have been associated with increased oocyte quality when in follicular fluid and secrete reactive oxygen species that are beneficial during placental angiogenesis. However, other bacteria, including Enterococcus, Staphylococcus, and Streptococcus, may modulate T helper cells that inhibit maternal recognition of pregnancy. Available data on the reproductive microbiome focus on variations in microbial communities and their associations with reproductive performance. However, research on these host-microbiome interactions may provide more insight on how bacteria affect fertility.

Milk fermented with Lactobacillus rhamnosus R0011 induces a regulatory cytokine profile in LPS-challenged U937 and THP-1 macrophages

Fermented dairy products have become attractive functional foods for the delivery of probiotics and their biologically active metabolites. The aim of this study was to examine the immunomodulatory activity of milk fermented with the probiotic lactic acid bacterium Lactobacillus rhamnosus R0011 (LrF) on macrophages challenged with lipopolysaccharide (LPS), a potent pro-inflammatory stimulus. To this end, human THP-1 or U937 monocytes were differentiated into resting macrophages then stimulated with LPS and co-incubated with the LrF or with milk controls. Levels of pro-inflammatory and immunoregulatory cytokines were determined by enzyme-linked immunosorbent assays. Culturing of LPS-stimulated U937 macrophages with either the whole or filtered LrF resulted in an increase in Interleukin (IL)-1Ra production relative to the negative control. THP-1 macrophages cultured with the LrF demonstrated an increase in LPS-induced IL-10 and IL-1β production, while production of LPS-induced IL-6, sCD54, IL-8, IL-1β, TNF-α, IL-12p70 and Transforming Growth Factor-β (TGF-β) was unaffected. Further, the LrF induced the expression of DC-SIGN and CD206, markers of immunoregulatory M2 macrophage polarization, in LPS-challenged THP-1 macrophages. Taken together, milk fermented with L. rhamnosus R0011 increased regulatory cytokine production from LPS-challenged U937 and THP-1 macrophages, while simultaneously up-regulating the production of IL-1β and expression of DC-SIGN and CD206, a profile characteristic of polarization into the immunoregulatory M2 macrophage phenotype.

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Milk fermented with Lactobacillus rhamnosus R0011 (Lrf) induces a regulatory macrophage phenotype.

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Modulation of cytokine profiles induced by lipopolysaccharide challenge consistent with an alternatively activated (M2) macrophage phenotype.

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Fermented milk conditioning induced macrophage expression of genes characteristic of M2 macrophage polarization (DC-SIGN and CD206).

A comprehensive post-market review of studies on a probiotic product containing Lactobacillus helveticus R0052 and Lactobacillus rhamnosus R0011

The probiotic preparation Lacidofil® has been commercially available in Europe, Asia and North America since 1995. This product is a combination of two strains, Lactobacillus helveticus R0052 and Lactobacillus rhamnosus R0011. The strains have been evaluated for safety, identity and mechanisms of probiotic action in vitro, in animal models and human clinical trials. The strains adhered to human epithelial cells, helped to maintain the barrier function and blocked the adhesion of a number of pathogens, allowing them to be cleared from the intestine. The strains also elicited an anti-inflammatory response by down-regulating IL-1β, IL-8 and TNF-α. In various stress models, the probiotic combination facilitated better coping and outcomes which may be through the maintenance of barrier function and suppressing inflammation. Overall, pre-clinical studies suggest a potential anti-infectious role for the strains and the combination. Clinical studies, primarily in children, have identified Lacidofil as an effective supplement for various gastrointestinal diseases such as antibiotic-associated diarrhoea and acute gastroenteritis. Recent research has also indicated that Lacidofil may be beneficial for individuals with atopic dermatitis or vaginal dysbacteriosis.

Age-related decline in macrophage and lymphocyte functions in mice and its alleviation by treatment with probiotic Dahi containing Lactobacillus acidophilus and Bifidobacterium bifidum

This study evaluated the effects of probiotic Dahi administration in ageing mice on macrophage and lymphocyte functions. Probiotic Dahi were prepared by co-culturing in buffalo milk (3% fat) Dahi bacteria (Lactococcus lactis ssp. cremoris NCDC-86 and Lc. lactis ssp. lactis biovar diacetylactis NCDC-60) along with Lactobacillus acidophilus LaVK2 (La-Dahi) or combined Lb. acidophilus and Bifidobacterium bifidum BbVK3 (LaBb-Dahi). Four groups of 12 mo old mice were fed for four months, with the supplements (5 g/day) of buffalo milk (3% fat), Dahi, La-Dahi and LaBb-Dahi, respectively, in addition to basal diet, and a fifth group that received no supplements served as control. The immune functions of young mice (4 mo old) were also compared with those of ageing adult mice (16 mo old). The production of nitric oxide and cytokines IL-6 and TNF-α declined and that of immunosuppressive prostaglandin E2 (PGE2) increased by stimulated peritoneal and splenic macrophages in ageing mice, compared with their young counterparts. The proliferation of stimulated splenocytes diminished and the production of IL-2 decreased and that of IL-6 and TNF-α enhanced in ageing compared with young mice. Feeding ageing mice with La-Dahi or LaBb-Dahi improved peritoneal macrophage functions stimulating nitric oxide and IL-6 and diminishing PGE2 production. Feeding La-Dahi or LaBb-Dahi also improved lymphocyte functions stimulating their proliferation and production of IL-2 in ageing mice. To conclude, the probiotic La-Dahi and LaBb-Dahi are effective in reversing age related decline in immune functions in mice.