Combined effects of BARLEYmax and cocoa polyphenols on colonic microbiota and bacterial metabolites in vitro.

BARLEYmax, a barley variety, and cocoa polyphenols (CPPs) have been reported to affect bacterial metabolites in the colon. This study aimed to evaluate the combined effects of BARLEYmax and CPPs supplementation on fecal microbiota in vitro using pig feces for 48 h. The relative abundances of the family Clostridiaceae and the genus Clostridium and ammonia-nitrogen production were decreased by both BARLEYmax and CPP supplementation, and there was a positive correlation between their abundances and the ammonia-nitrogen concentration. Although acetate and n-butyrate production was decreased by CPP supplementation, their concentrations were maintained at a higher level in the BARLEYmax + CPP group than in the cellulose (control) and cellulose + CPP groups. Therefore, this study demonstrated that a combination of BARLEYmax and CPPs may be beneficial in maintaining higher short-chain fatty acid production and the elimination of potentially harmful factors. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1007/s10068-021-00959-z.

Medium-chain triacylglycerol suppresses the decrease of plasma albumin level through the insulin-Akt-mTOR pathway in the livers of malnourished rats.

Recent studies have shown that medium-chain triacylglycerol (MCT) improved serum albumin concentration in elderly people with protein-energy malnutrition (PEM) and in malnourished rats. However, the mechanism for this effect has not been clarified. Dietary MCT promotes insulin secretion from the pancreas, and insulin activates mammalian target of rapamycin (mTOR) complex 1 (mTORC1) via the activation of phosphoinositide 3-kinase (PI3K) and its downstream effecter, Akt. mTORC1 promotes mRNA translation through S6K and 4E-BP1. Therefore, we hypothesized that dietary MCT elevates albumin synthesis through promotion of insulin-Akt-mTOR transduction in the liver. To test this hypothesis, we measured phosphorylated Akt, mTOR and albumin in the livers of malnourished rats. In the present study we examined rats fed low-protein diets containing either MCT or long-chain triacylglycerol (LCT) with energy restriction. The plasma and liver albumin levels were significantly higher in the MCT-fed group than in the LCT-fed group. In addition, plasma insulin concentration, liver phosphorylated Akt/Akt and phosphorylated mTOR/mTOR levels were significantly higher in the MCT-fed group than in the LCT-fed group. These results suggest that one of the mechanisms for the albumin improvement effect of dietary MCT is the promotion of albumin synthesis through the insulin-Akt-mTOR signaling pathway of the liver.

The change in conjugated linoleic acid concentration in blood of Japanese fed a conjugated linoleic acid diet.

Conjugated linoleic acid (CLA) is a collective term used for fatty acids with a conjugated double bond that are geometrical and positional isomers of linoleic acid. Anti-obesity and anti-cancer properties, an immunopotentiation effect, and promotion of bone formation by CLA have been shown in cell culture and animal studies. A mixture of 9c11t- and 10t12c-CLA is now used as a health food supplement after testing in clinical trials. These trials focused on improvement of lipid metabolism by CLA, whereas few studies have examined absorption and metabolism of CLA in humans. In addition, there is no report concerning absorption and metabolism of CLA in Japanese. This study was designed to examine CLA concentration in blood, the elimination rate of CLA, and metabolic differences between 9c11t-CLA and 10t12c-CLA in blood in Japanese who ingested CLA (about 2 g/d, equal weights of 9c11t-CLA and 10t12c-CLA) for 3 wk. Blood samples were collected 1 wk before the 3-wk period, on the first and last days of the period, and 1 wk after the end of the period, and the CLA concentration and distribution in blood were investigated. The CLA concentration in blood was significantly increased by CLA ingestion and reached 36 µmol/L. The CLA concentration in blood one week after the intake period was significantly lower than that at the end of CLA intake. The 10t12c-CLA level in plasma decreased faster than that of 9c11t-CLA. This suggests faster metabolism (fatty acid ß oxidation) of 10t12c-CLA compared with 9c11t-CLA.

Decrease of food intake in rats after ingestion of medium-chain triacylglycerol.

Previous studies have demonstrated that fatty acid oxidation in the liver may affect food intake. This study examined the influence of preloading of medium-chain triacylglycerol (MCT) on food intake in comparison with long-chain triacylglycerol (LCT). Male rats were fasted for 18 h and then administered LCT or MCT emulsion orally. Each group of rats was allowed to rest for 30 min, and then food intake during 1 h was measured. Food intake in the MCT group was significantly lower than that in the LCT group. To examine the influence of hepatic oxidation, the MCT+MA group was injected intraperitoneally with mercaptoacetate (MA), an inhibitor of fatty acid oxidation, 2 h before ingestion of MCT emulsion. Then, 30 min after ingestion of LCT or MCT emulsion, food intake was measured for 1 h. Food intake in the MCT group was significantly lower than that in the LCT group, but there was no significant difference between the MCT+MA group and the LCT group. Food intake in the MCT+MA group was significantly higher than that in the MCT group. The hepatic ATP content after MCT ingestion was significantly higher than that after LCT ingestion, but there was no significant difference between the MCT+MA group and the LCT group. The hepatic ATP content after MCT+MA ingestion was significantly lower than that after MCT ingestion. These results suggest that ingestion of medium-chain fatty acid (MCFA) increases the liver ATP content in fasted rats, consequently decreasing food intake.

A good response to oil with medium- and long-chain fatty acids in body fat and blood lipid profiles of male hypertriglyceridemic subjects.

A double blind clinical trial was carried out to clarify the effects of oil with medium- and long-chain triglyceride (MLCT) on body fat and blood lipid profiles in hypertriglyceridemic subjects. One-hundred-and-twelve subjects were enrolled and divided into two groups; those that consumed MLCT oil and those that consumed long-chain triglyceride (LCT) oil for 8 weeks. All subjects were requested to consume 25-30 g of the oils daily and maintain a fixed level of energy intake and exercise. Anthropometric and blood biochemical parameters were measured when the study was initiated and completed. The LCT group consisted of 50 subjects (34 men and 16 women), while the MLCT group consisted of 51 subjects (33 men and 18 women) who completed the study. Larger decreases in body weight, body mass index, waist circumference, body fat, total fat area and subcutaneous fat area in the abdomen and serum triglycerides, low-density lipoprotein cholesterol, apolipoprotein B, C2, C3 and E were observed in male subjects in the MLCT group than those in the LCT group. However, no significant differences in these parameters between the female subjects in the two groups were observed. Data from this study indicate that consumption of medium-and long-chain triglycerides can reduce body weight and body fat and improve blood lipid profiles in male hypertriglyceridemic subjects.

Chinese hypertriglycerideamic subjects of different ages responded differently to consuming oil with medium- and long-chain fatty acids.

Two groups of Chinese hypertriacylglycerolemic subjects were recruited and randomized to medium- and long-chain triacylglycerols (MLCT) oil or long-chain triacylglycerols (LCT) oil. Two subgroups were divided by age at less or more 60 years in both groups. Both oils were consumed at 25-30 g daily for 8 weeks. Anthropometry, blood biochemicals, and computed tomography (CT) scanning were done at the initial and final times. In subjects of age less than 60 years on MLCT, the body weight, body mass index (BMI), waist circumference (WC), hip circumference (HC), waist-hip ratio (WHR), body fat, total fat area, and subcutaneous fat area were significantly lower than those of the initial values, and the change values in these indicators and visceral fat area lowered significantly as compared with those on LCT. The levels of apoB, apoA2, apoC2, and apoC3 decreased significantly, and the change in values in the levels of triglyceride (TG), low-density lipoprotein cholesterol (LDL-C), apoA1, apoB, apoA2, apoC2, apoC3 were significantly lower on MLCT of age under 60 years as compared with those on LCT.

The application of medium-chain fatty acids: edible oil with a suppressing effect on body fat accumulation.

The bulk of fatty acids found in our diets consists of long-chain fatty acids (LCFA), which are molecules containing 12 or more carbon atoms. In contrast, medium-chain fatty acids (MCFA) are composed of 8-10 carbon atoms, and are found in palm kernel oil, among other types of foods. MCFA have attracted attention as being part of a healthy diet, because they are absorbed directly into the portal vein, transported rapidly to the liver for beta-oxidation, and thus increase diet-induced thermogenesis. In contrast, long-chain triacylglycerols are absorbed via the intestinal lymphatic ducts and transported by chylomicrons through the thoracic duct into the systemic circulation. Because medium-chain triacylglycerols (MCT) containing solely MCFA have a few disadvantages when used for deep frying, we have developed a new kind of triacylglycerol product: medium- and long-chain triacylglycerol (MLCT). MLCT is produced by lipase-catalyzed enzymatic transesterification. Long-term clinical trials have demonstrated that MLCT and MCT result in less body fat accumulation in humans. MLCT oil has been approved as FOSHU (Food for Specified Health Use) for use as cooking oil with a suppressing effect on body fat accumulation.

Alpha-linolenic acid-rich flaxseed oil ingestion increases plasma adiponectin level in rats.

Adiponectin, an adipose-specific secretory protein, exhibits antidiabetic and antiatherogenic properties. The effect of alpha-linolenic acid (ALA) on adiponectin has not been revealed. ALA is included abundantly in vegetable oils such as flaxseed oil. In this study, we attempted to clarify the effect of ALA-rich flaxseed oil (FSO) intake on the adiponectin level in rats. Seven-week-old male Sprague-Dawley rats were fed test diets containing high oleic safflower oil (HOSO) or FSO for 4 weeks. After the experimental period, the plasma adiponectin concentration in the FSO-fed group was higher than that in the HOSO-fed group. The adiponectin content of perirenal adipose tissue in the FSO-fed group was also significantly higher than that in the HOSO-fed group. However, the adiponectin mRNA level in the perirenal adipose tissue did not differ significantly between the HOSO-fed and FSO-fed groups. In this study, we clarified the effect of the ALA-rich FSO ingestion on the plasma adiponectin concentration in rats. It was suggested that the ALA-rich FSO intake might exhibit beneficial effects through an increase of the adiponectin level.

Effects of phytosterol ester-enriched vegetable oil on plasma lipoproteins in healthy men.

It has been reported that phytosterol esters reduce cholesterol absorption and lower serum cholesterol concentration. There have been very few studies published on the effect of dose of phytosterol esters less than 1.0 g/day on plasma cholesterol levels in healthy subjects using commonly consumed foods. In this study, we evaluated the effect of 0.45 g/day (as free sterol) phytosterol ester-enriched dissolved in vegetable oil on plasma lipoproteins in sixty healthy males with slightly elevated total cholesterol concentration. This study was conducted in a randomized, double-blind, placebo-controlled, and arm parallel study. A total of 14 g/day of phytosterol ester-enriched vegetable oil containing 0.45 g phytosterol (as the major free sterol) was compared with a control vegetable oil containing 0.04 g phytosterol (as the major free sterol). All subjects did not change their usual dietary habit and consumed foods that included about 360 mg/day cholesterol for 12 weeks. In subjects with higher total cholesterol concentrations (>200mg/dL), the phytosterol enriched-vegetable oil significantly reduced total cholesterol (10.3%, P<0.05), very low density (VLDL) lipoprotein cholesterol (22.5%, P<0.05), and remnant-like lipoprotein (RLP) cholesterol (24.7%, P<0.01) compared with the control vegetable oil. A reduction in low density lipoprotein (LDL) cholesterol concentration was also observed. In particular, the improvement in serum lipoprotein was more pronounced in subjects with higher total cholesterol concentrations. Triglycerides and high density lipoprotein (HDL) cholesterol did not change significantly. Plasma concentration of fat-soluble vitamins (tocopherol and retinol) and beta-carotene were not statistically significantly affected by phytosterol ester-enriched vegetable oil. These findings indicate that a daily consumption of phytosterol ester as low as 0.45 g/day (as free sterol) is effective in lowering blood total cholesterol concentration and RLP cholesterol concentration. Lower total cholesterol, VLDL cholesterol and RLP cholesterol due to consumption of the phytosterol ester-enriched vegetable oil may be helpful in reducing the risk of CHD in the population.