Live probiotic bacteria are effective in reducing gut permeability and inflammation. We have previously shown that probiotics release peptide bioactive factors that modulate epithelial resistance in vitro. The objectives of this study were to determine the impact of factors released from Bifidobacteria infantis on intestinal epithelial cell permeability and tight junction proteins and to assess whether these factors retain their bioactivity when administered to IL-10-deficient mice. B. infantis conditioned medium (BiCM) was applied to T84 human epithelial cells in the presence and absence of TNF-alpha and IFN-gamma. Transepithelial resistance (TER), tight junction proteins [claudins 1, 2, 3, and 4, zonula occludens (ZO)-1, and occludin] and MAP kinase activity (p38 and ERK) were examined. Acute effects of BiCM on intestinal permeability were assessed in colons from IL-10-deficient mice in Ussing chambers. A separate group of IL-1-deficient mice was treated with BiCM for 4 wk and then assessed for intestinal histological injury, cytokine levels, epithelial permeability, and immune response to bacterial antigens. In T84 cells, BiCM increased TER, decreased claudin-2, and increased ZO-1 and occludin expression. This was associated with enhanced levels of phospho-ERK and decreased levels of phospho-p38. BiCM prevented TNF-alpha- and IFN-gamma-induced drops in TER and rearrangement of tight junction proteins. Inhibition of ERK prevented the BiCM-induced increase in TER and attenuated the protection from TNF-alpha and IFN-gamma. Oral BiCM administration acutely reduced colonic permeability in mice whereas long-term BiCM treatment in IL-10-deficient mice attenuated inflammation, normalized colonic permeability, and decreased colonic and splenic IFN-gamma secretion. In conclusion, peptide bioactive factors from B. infantis retain their biological activity in vivo and are effective in normalizing gut permeability and improving disease in an animal model of colitis. The effects of BiCM are mediated in part by changes in MAP kinases and tight junction proteins.
ALA is rare and the incidence has decreased in USA. Young, Hispanic males in southwestern states are most frequently affected. Mortality caused by ALA is lower than what was reported previously.
The fatty acids, linoleic acid (18:2ω-6) and α-linolenic acid (18:3ω-3), are essential to the human diet. When these essential fatty acids are not provided in sufficient quantities, essential fatty acid deficiency (EFAD) develops. This can be suggested clinically by abnormal liver function tests or biochemically by an elevated Mead acid and reduced linoleic acid and arachidonic acid level, which is manifested as an elevated triene/tetraene ratio of Mead acid/arachidonic acid. Clinical features of EFAD may present later. With the introduction of novel intravenous (IV) lipid emulsions in North America, the proportion of fatty acids provided, particularly the essential fatty acids, varies substantially. We describe a case series of 3 complicated obese patients who were administered parenteral nutrition (PN), primarily using ClinOleic 20%, an olive oil-based lipid emulsion with reduced amounts of the essential fatty acids, linoleic and α-linolenic, compared with more conventional soybean oil emulsions throughout their hospital admission. Essential fatty acid profiles were obtained for each of these patients to investigate EFAD as a potential cause of abnormal liver enzymes. Although the profiles revealed reduced linoleic acid and elevated Mead acid levels, this was not indicative of the development of essential fatty acid deficiency, as reflected in the more definitive measure of triene/tetraene ratio. Instead, although the serum fatty acid panel reflected the markedly lower but still adequate dietary linoleic acid content and greatly increased oleic acid content in the parenteral lipid emulsion, the triene/tetraene ratio remained well below the level, indicating EFAD in each of these patients. The availability and use of new IV lipid emulsions in PN should encourage the clinician to review lipid metabolism based on the quantity of fatty acids provided in specific parenteral lipid emulsions and the expected impact of these lipid emulsions (with quite different fatty acid composition) on measured fatty acid profiles.
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