g., butyrate). Supplementing the diet with probiotic bacteria can increase small intestine Repotrectinib mw absorption of nutrients [14–16] and electrolytes , and when added to culture media increase calcium uptake by Caco-2 cells . Microarray analyses have revealed that long-term exposure
to commensal bacteria and specific strains of probiotics (i.e., Lactobacillus GG) up-regulates genes involved in postnatal intestinal maturation, angiogenesis, and mucosal barrier functions, whereas genes associated with apoptosis and inflammation were down-regulated . Absorption of glucose by enterocytes is mediated in part by the concentrative, high affinity, sodium-dependent glucose transporter (SGLT1), with rates of uptake dependent on the densities and activities of the SGLT1. Historically, studies of glucose uptake regulation have focused on the patterns of gene expression (genomic regulation), leading to changes
YM155 supplier in the abundances of transporter proteins. This include responses to bacterial lipopolysaccharides . Enterocytes also have the ability to rapidly (<10 min) and reversibly regulate nutrient absorption independent of changes in the total cellular abundance of transporter Saracatinib clinical trial proteins [21–24]. This non-genomic regulation of nutrient transporters allows enterocytes to adapt to the transient changes in luminal nutrient concentrations that occur before, during,
and after the processing of meals. Previous studies have reported the influences of probiotic bacteria on nutrient absorption, but have used prolonged periods of administration or exposure (6 h to days and weeks). As a result, the reported responses can be attributed to genomic regulation of the transporters. The present study demonstrates for the first time that metabolites produced by probiotic Lactobacillus acidophilus and four other species of Lactobacilli upregulate enterocyte glucose transport within 10 min of exposure using Caco-2 cells as a model Fossariinae for the intestine. Results Growth of Bacteria Based on increases in absorption measured at 600 nm, the CDM-fructose and CDM-mannose elicited similar patterns of growth for L. acidophilus (Figure 1). However, after 80 h of anaerobic culture densities in CDM-fructose and CDM-mannose (108 CFU/ml) were lower compared to MRS broth (109 CFU/ml; P < 0.0001). Although CDM-glucose elicited an earlier increase in growth compared with CDM with fructose and mannose (shorter lag time), densities at 80 h were not higher compared with CDM-fructose and CDM-mannose cultures. The CDM alone or with arabinose, ribose, and xylose did not support the growth of L. acidophilus. Figure 1 Growth curves of Lactobacillus acidophilus.