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Objective COVID-19 has affected people’s health in various ways. University students are a particularly sensitive group for mental and physical health issues. The aim of this study was to assess and compare the mental and physical health of male and female first-year university students during and before COVID-19. Method Total of 115 first-year university students (54% male) answered questions about mental and physical health. The students were asked to estimate their physical activity, sedentary behavior, loneliness, stress, and sleep quality during COVID-19 opposed to before the pandemic. Result Males had fewer symptoms of anxiety and depression, and their self-esteem was higher than females (p Conclusion University students estimated their mental and physical health to have deteriorated during the pandemic. Therefore, it is important that the school and healthcare systems assist students in unwinding these negative health and lifestyle changes that have accompanied the pandemic.

Short-chain fatty acids (SCFAs), particularly propionic and butyric acids, have been shown to have many positive health effects. The amount and type of SCFAs formed from dietary fibre by the colonic microbiota depends on the substrate available and is reflected in blood. The total intake and type of dietary fibre in people with gastrointestinal diseases differs considerably from healthy subjects.To compare fasting SCFA concentrations in subjects with microscopic colitis (MC), celiac disease and controls without these diseases. SCFAs were also analysed over 6.5 h in young healthy subjects, who had eaten a fibre-rich breakfast, to identify a possible peak concentration of SCFAs after a meal.SCFAs in serum were pre-concentrated using hollow fibre-supported liquid membrane extraction and gas chromatography.The MC group had a higher concentration of valeric acid than the control group (p0.01). No significant differences in other SCFA concentrations were seen between groups, but the control group tended to have higher concentration of acetic acid (p = 0.1). Furthermore, males had higher concentrations of SCFAs (with the exception of valeric acid) than females (p0.05), which were independent of groups. The peaks for acetic, propionic and butyric acids came approximately 5 h, 6.5 h and 2-3 h, respectively, after breakfast.The fasting concentrations of SCFAs were quite similar, although the fibre intake had probably been quite different for a long time. The results might have been different if SCFAs had been recorded over a longer period.

Ragnhild Undseth,1 Greta Jakobsdottir,2 Margareta Nyman,2 Arnold Berstad,3 Jørgen Valeur3 1Department of Radiology, Lovisenberg Diaconal Hospital, Oslo, Norway; 2Food for Health Science Centre, Lund University, Lund, Sweden; 3Unger-Vetlesen Institute, Lovisenberg Diaconal Hospital, Oslo, Norway Background: Ingestion of low-digestible carbohydrates triggers symptoms in patients with irritable bowel syndrome (IBS). These carbohydrates become substrates for microbial fermentation in the colon, yielding short-chain fatty acids (SCFAs) that are readily absorbed. Aiming to compare colonic fermentation in patients with IBS and healthy controls, we analyzed the concentrations of SCFA in serum at fasting and 90 minutes following ingestion of an unabsorbable, but fermentable carbohydrate, lactulose. Methods: Patients with IBS according to Rome III criteria (n=22) and healthy controls (n=20) ingested 10 g lactulose dissolved in water. Symptoms were graded by questionnaires and SCFA were analyzed using hollow fiber-supported liquid membrane extraction coupled with gas chromatography. Results: Lactulose induced more symptoms in patients with IBS than in healthy controls (P=0.0001). Fasting serum levels of SCFA did not differ between patients with IBS and controls. However, the postprandial levels of total SCFA (P=0.0002), acetic acid (P=0.005), propionic acid (P=0.0001), and butyric acid (P=0.01) were significantly lower in patients with IBS compared with healthy controls. There was no correlation between the levels of serum SCFA and symptom severity. Conclusion: Low-serum levels of SCFA after lactulose ingestion may indicate impaired colonic fermentation in patients with IBS. Conceivably, this disturbance is related to symptom generation, but the mechanism is not clear. Keywords: fermentation, FODMAP, irritable bowel syndrome, microbiota, short-chain fatty acids&nbsp

Dietary fiber and flavonoids, important components in berries, are suggested to improve metabolic health. This study investigates whether soluble and insoluble fractions isolated from bilberry, black currant, and raspberry affect the formation of short-chain fatty acids (SCFAs), uptake and excretion of flavonoids, and levels of cholesterol differently. Cecal SCFA pools were higher in rats fed the soluble than the insoluble fractions (525 vs 166 μmol, P < 0.001), whereas higher concentrations of butyric acid were found in the distal colon and serum of rats fed the insoluble fractions (5 vs 3 μmol/g and 58 vs 29 μmol/L, respectively, P < 0.001). The soluble bilberry fraction gave lower amounts of liver cholesterol (56 mg) than the other berry fractions (87 ± 5 mg), formed the highest amount of SCFAs (746 vs 266 ± 21 μmol), and contributed the highest intake of anthocyanins. Cyanidin-3-glucoside monoglucuronide was detected in the urine of all groups, whereas anthocyanins were found only in groups fed soluble black currant and raspberry.

Introduction Obesity is linked to type 2 diabetes and risk factors associated to the metabolic syndrome. Consumption of dietary fibres has been shown to have positive metabolic health effects, such as by increasing satiety, lowering blood glucose and cholesterol levels. These effects may be associated with short-chain fatty acids (SCFAs), particularly propionic and butyric acids, formed by microbial degradation of dietary fibres in colon, and by their capacity to reduce low-grade inflammation. Objective To investigate whether dietary fibres, giving rise to different SCFAs, would affect metabolic risk markers in low-fat and high-fat diets using a model with conventional rats for 2, 4 and 6 weeks. Material and Methods Conventional rats were administered low-fat or high-fat diets, for 2, 4 or 6 weeks, supplemented with fermentable dietary fibres, giving rise to different SCFA patterns (pectin – acetic acid; guar gum – propionic acid; or a mixture – butyric acid). At the end of each experimental period, liver fat, cholesterol and triglycerides, serum and caecal SCFAs, plasma cholesterol, and inflammatory cytokines were analysed. The caecal microbiota was analysed after 6 weeks. Results and Discussion Fermentable dietary fibre decreased weight gain, liver fat, cholesterol and triglyceride content, and changed the formation of SCFAs. The high-fat diet primarily reduced formation of SCFAs but, after a longer experimental period, the formation of propionic and acetic acids recovered. The concentration of succinic acid in the rats increased in high-fat diets with time, indicating harmful effect of high-fat consumption. The dietary fibre partly counteracted these harmful effects and reduced inflammation. Furthermore, the number of Bacteroides was higher with guar gum, while noticeably that of Akkermansia was highest with the fibre-free diet.

The metabolic syndrome (MetS), characterized by obesity, hyperlipidemia, hypertension, and insulin resistance, is a growing epidemic worldwide, requiring new prevention strategies and therapeutics. The concept of prebiotics refers to selective stimulation of growth and/or activity(ies) of one or a limited number of microbial genus(era)/species in the gut microbiota that confer(s) health benefits to the host. Sequencing the gut microbiome and performing metagenomics has provided new knowledge of the significance of the composition and activity of the gut microbiota in metabolic disease. As knowledge of how a healthy gut microbiota is composed and which bacterial metabolites are beneficial increases, tailor-made dietary interventions using prebiotic fibers could be developed for individuals with MetS. In this review, we describe how dietary fibers alter short-chain fatty acid (SCFA) profiles and the intrinsic and extrinsic effects of prebiotics on host metabolism. We focus on several key aspects in prebiotic research in relation to MetS and provide mechanistic data that support the use of prebiotic fibers in order to alter the gut microbiota composition and SCFA profiles. Further studies in the field should provide reliable mechanistic and clinical evidence for how prebiotics can be used to alleviate MetS and its complications. Additionally, it will be important to clarify the effect of individual differences in the gut microbiome on responsiveness to prebiotic interventions.

SCFA are important end products formed during colonic fermentation of dietary fibre (DF). It has been suggested that propionic and butyric acids affect metabolic parameters, low-grade systemic inflammation, insulin resistance and obesity. The aim of the present study was to investigate whether the various SCFA profiles observed after fermentation in the caecum of rats fed pectin, guar gum and fructo-oligosaccharides (FOS) were also represented in hepatic portal and aortic serum. The SCFA in serum were extracted using hollow fibre-supported liquid membrane extraction before GLC analysis. The concentrations of acetic, propionic and butyric acids in caecal content correlated well with those in portal serum (PPP= 0·019) of rats fed FOS. FOS gave rather low amounts of the SCFA, especially butyric acid, but caecal tissue weight was higher with FOS than with the other two diets. This may be explained by rapid fermentation and quick utilisation/absorption of the SCFA. The present study also showed that propionic acid was metabolised/utilised to a higher extent than butyric acid by colonocytes before reaching the liver. We conclude that the formation of propionic and butyric acids in the caecum is reflected by increased concentrations in the aortic blood. This approach may therefore simplify the evaluation and study of SCFA from DF in human subjects.

The aim of this study was to investigate how physico-chemical properties of two dietary fibres, guar gum and pectin, affected weight gain, adiposity, lipid metabolism, short-chain fatty acid (SCFA) profiles and the gut microbiota in male Wistar rats fed either low- or high-fat diets for three weeks. Both pectin and guar gum reduced weight gain, adiposity, liver fat and blood glucose levels in rats fed a high-fat diet. Methoxylation degree of pectin (low, LM and high (HM)) and viscosity of guar gum (low, medium or high) resulted in different effects in the rats, where total blood and caecal amounts of SCFA were increased with guar gum (all viscosities) and with high methoxylated (HM) pectin. However, only guar gum with medium and high viscosity increased the levels of butyric acid in caecum and blood. Both pectin and guar gum reduced cholesterol, liver steatosis and blood glucose levels, but to varying extent depending on the degree of methoxylation and viscosity of the fibres. The medium viscosity guar gum was the most effective preparation for prevention of diet-induced hyperlipidaemia and liver steatosis. Caecal abundance of Akkermansia was increased with high-fat feeding and with HM pectin and guar gum of all viscosities tested. Moreover, guar gum had distinct bifidogenic effects independent of viscosity, increasing the caecal abundance of Bifidobacterium ten-fold. In conclusion, by tailoring the viscosity and possibly also the degree of methoxylation of dietary fibre, metabolic effects may be optimized, through a targeted modulation of the gut microbiota and its metabolites.