Effects of an Exopolysaccharide (Kefiran) from Lactobacillus kefiranofaciens on Blood Glucose in KKAy Mice and Constipation in SD Rats Induced by a Low-Fiber Diet

In vivo functional effects of Weissella confusa VP30 exopolysaccharides on loperamide-induced constipation in rats

In this work, the in vivo functionalities of milk fermented with Weissella confusa VP30 (VP30-EPS) and purified exopolysaccharide (pEPS) from the milk fermented with Weissella confusa VP30 were evaluated for their effect on constipation using an experimental constipated rat model. Rats were randomly divided into four groups: (i) control group (PBS administered normal group), (ii) loperamide treated group (constipation group), (iii) constipation with loperamide plus VP30-EPS (1 g/kg), and (iv) constipation with loperamide plus pEPS (0.6 g/kg) groups. Loperamide treatment induced animal constipation and significantly reduced the frequency of defecation, intestinal transit ratio, and water content of feces. However, all four fecal parameters were improved in both the loperamide plus VP30-EPS and pEPS administered groups as compared to the loperamide group. These results suggest that the addition of VP30-EPS potentially improves the functional laxative effects of commercial products. This study suggests the possibility that VP30-EPS can be applied to fermented and/or functional foods to relieve constipation.

A review of nondairy kefir products: their characteristics and potential human health benefits

Functional foods are foods that, in addition to having nutrients, contain in their composition ingredients that act specifically on body functions associated with the control and reduction of the risk of developing some diseases. In this sense, kefir, a group of microorganisms in symbiosis, mainly yeasts and lactic acid bacteria, stands out. The trend of ingesting kefir has been focused on the development of products that serve specific consumers, such as those who are lactose-intolerant, vegans and vegetarians, and consumers in general who seek to combine the consumption of functional products with the improvement of their health and lifestyle. This overview provides an insight into kefir, presenting the technological process to produce a nondairy beverage and evidence of the benefits of its use to reduce the risk of disease. We also discuss regulatory aspects of products fermented using kefir. Until now, the use of kefir (isolated microorganism, kefiran, or fermented product) has demonstrated the potential to promote an increase in the number of bifidobacteria in the colon and an increase in the glycemic control while reducing the blood cholesterol and balancing the intestinal microbiota, which helps in reducing constipation and diarrhea, improving intestinal permeability, and stimulating and balancing the immune system. However, the literature still has gaps that need to be clarified, such as the consumption dose of kefir or its products to cause some health benefit.

Kefiran ameliorates malfunctions in primary and functional immune cells caused by lipopolysaccharides

Kefiran is a water-soluble polysaccharide well recognized as a bioactive ingredient to enhance nutritional and health-promoting features. Also, some therapeutic properties have made this macromolecule an active ingredient in ointments and oral anti-inflammatory drugs. However, the details of the molecular and cellular aspects of these effects have not been addressed. In this study, lipopolysaccharides (LPS)-induced monocytes, lymphocytes, and monocyte-derived dendritic cells (MDDCs) as representative cells for both innate and adaptive immunity were treated with kefiran for 2 h. Kefiran had an anti-inflammatory effect on monocytes to reduce pro-inflammatory cytokines, interleukin 1 β (IL-1β) & tumor necrosis factor α (TNF-α), as well as nuclear factor kappa b (NF-kb). However, it did not affect lymphocytes. Overexpression of Toll-like receptor 4 (TLR4) in LPS-induced cells was not reduced after kefiran treatment. Kefiran balanced MDDCs secretion of pro/anti-inflammatory cytokines by reducing and enhancing the expression of IL-1β and interleukin 10 (IL-10), respectively. Also, kefiran decreased the number of apoptotic immature MDDCs and promoted dose-dependent phagocytosis capacity of MDDCs. According to the results of the current study, it may be concluded that the immunomodulatory effects of kefiran are due to antagonist against innate immune receptors especially TLR4. The results of this study can be used as a guide to developing kefiran-based non-aggressive anti-inflammatory drugs. Furthermore, understanding the immunobiological effects of kefiran on monocytes and lymphocytes was another outcome of this study.

Antiobesity Effect of Exopolysaccharides Isolated from Kefir Grains

Physiological properties of water-soluble exopolysaccharides (EPS) and residues after EPS removal (Res) from the probiotic kefir were determined in high-fat (HF) diet-fed C57BL/6J mice. EPS solutions showed rheological properties and lower viscosity compared to those of β-glucan (BG). EPS significantly suppressed the adipogenesis of 3T3-L1 preadipocytes in a dose-dependent manner. Mice were fed HF diets containing 5% EPS, 5% BG, 8% Res, or 5% microcrystalline cellulose (control) for 4 weeks. Compared with the control, EPS supplementation significantly reduced HF diet-induced body weight gain, adipose tissue weight, and plasma very-low-density lipoprotein cholesterol concentration (P < 0.05). Res and BG significantly reduced body weight gain; however, reduction in adipose tissue weight was not statistically significant, suggesting that the antiobesity effect of EPS occurs due to viscosity and an additional factor. EPS supplementation significantly enhanced abundance of Akkermansia spp. in feces. These data indicate that EPS shows significant antiobesity effects possibly via intestinal microbiota alterations.

Food protein-derived bioactive peptides in management of type 2 diabetes

BACKGROUND

Type 2 diabetes (T2D), one of the major common human health problems, is growing at an alarming rate around the globe. Alpha-glucosidase and dipeptidyl peptidase IV (DPP-IV) enzymes play a significant role in development of T2D. Hence, reduction or inhibition of their activity can be one of the important strategies in management of T2D. Studies in the field of bioactive peptides have shown that dietary proteins could be natural source of alpha-glucosidase and DPP-IV inhibitory peptides.

PURPOSE

The purpose of this review is to provide an overview of food protein-derived peptides as potential inhibitors of alpha-glucosidase and DPP-IV with major focus on milk proteins.

METHODS

Efforts have been made to review the available information in literature on the relationship between food protein-derived peptides and T2D. This review summarizes the current data on alpha-glucosidase and dipeptidyl peptidase IV inhibitory bioactive peptides derived from proteins and examines the potential value of these peptides in the treatment and prevention of T2D. In addition, the proposed modes of inhibition of peptide inhibitors are also discussed.

RESULTS

Studies revealed that milk and other food proteins-derived bioactive peptides play a vital role in controlling T2D through several mechanisms, such as the satiety response, regulation of incretin hormones, insulinemia levels, and reducing the activity of carbohydrate degrading digestive enzymes.

CONCLUSIONS

The bioactive peptides could be used in prevention and management of T2D through functional foods or nutraceutical supplements. Further clinical trials are necessary to validate the findings of in vitro studies and to confirm the efficiency of these peptides for applications.

Laxative effects of Salecan on normal and two models of experimental constipated mice

Background

Constipation is one of the most common gastrointestinal complaints with a highly prevalent and often chronic functional gastrointestinal disorder affecting health-related quality of life. The aim of the present study was to evaluate the effects of Salecan on fecal output and small intestinal transit in normal and two models of drug-induced constipation mice.

Methods

ICR mice were administrated intragastrically (i.g.) by gavage with 100, 200 and 300 mg/kg body weight (BW) of Salecan while the control mice were received saline. The constipated mice were induced by two types of drugs, loperamide (5 mg/kg BW, i.g.) and clonidine (200 μg/kg BW, i.g.), after Salecan treatment while the control mice were received saline. Number, weight and water content of feces were subsequently measured. Small intestinal transit was monitored by phenol red marker meal.

Results

Salecan (300 mg/kg BW) significantly increased the number and weight of feces in normal mice. In two models of drug-induced constipation, Salecan dose-dependently restored the fecal number and fecal weight. The water content of feces was markedly affected by loperamide, but not by clonidine. Treatment with Salecan significantly raised the fecal water content in loperamide-induced constipation mice. Moreover, Salecan markedly stimulated the small intestinal transit in both loperamide- and clonidine-induced constipation model mice.

Conclusions

These results suggest that Salecan has a potential to be used as a hydrophilic laxative for constipation.

Kefiran reduces atherosclerosis in rabbits fed a high cholesterol diet

AIM

Kefiran is an exopolysaccharide produced by Lactobacillus kefiranofaciens, and has been proposed to have many health-promoting properties. We investigated the antiatherogenic effect of kefiran on rabbits fed a high-cholesterol diet.

METHODS

Male New Zealand White rabbits were fed a 0.5% cholesterol diet without (control group, n = 7) or with kefiran (kefiran group, n = 8) for eight weeks. The aorta was analyzed by histochemistry and atherosclerotic lesions were quantified. Lipids and sugars in serum were measured. Foam cell formation of RAW264.7 by βVLDL derived from both groups of rabbits was also investigated.

RESULTS

Cholesterol, triglyceride and phospholipids levels of serum and lipoprotein fractions were not significantly different between these groups. Atherosclerotic lesions of the aorta in the kefiran group were statistically lower than those of the control group, with marked differences in the abdominal aorta. T-lymphocytes were not detectable in the aorta of the kefiran group. Cholesterol contents in stools were almost identical in both groups. Cholesterol content in the liver of the kefiran group was statistically lower than in the control group. Galactose content of βVLDL derived from the kefiran group was higher, and the lipid peroxidation level was much lower than in the control group. RAW264.7 macrophages treated with βVLDL from the kefiran group showed a more spherical shape and accumulated statistically lower cholesterol than macrophages treated with βVLDL from the control group.

CONCLUSION

Orally derived kefiran is absorbed in the blood. Kefiran prevents the onset and development of atherosclerosis in hypercholesterolemic rabbits by anti-inflammatory and anti-oxidant actions.