Basics in clinical nutrition: Fibre and short chain fatty acids

Chronic Obstructive Pulmonary Disease: The Role of Healthy and Unhealthy Dietary Patterns-A Comprehensive Review

Chronic obstructive pulmonary disease (COPD) is a progressive and irreversible disease affecting many people worldwide. Recent evidence suggests that diet and lifestyle play a vital role in COPD progression. We aimed to provide a comprehensive review of the effect of healthy and unhealthy dietary patterns on preventing and treating COPD. For this reason, Scopus, EMBASE, Web of Science, and PubMed were searched. Based on our findings, it appears that adhering to a healthy dietary pattern rich in vegetables, legumes, fruit, nuts, and whole grains may have advantageous impacts on preventing and treating COPD while following an unhealthy dietary pattern rich in red and processed meat, saturated fats, sweets, and sugary drinks affect COPD negatively. Adhering to Mediterranean, dietary approaches to stop hypertension (DASH), Prudent, Ketogenic, and High-protein diet may be related to a lower risk of COPD and improved pulmonary function. Conversely, Western and Ramadan Intermittent Fasting diets may elevate the prevalence of COPD. Proposing a nutritious diet that enhances pulmonary function could potentially be an effective approach to preventing and managing COPD. A comprehensive knowledge of the relationship between dietary factors and COPD can provide healthcare professionals with properly supported approaches to advise patients and empower individuals to make informed lifestyle decisions that are beneficial to improve their pulmonary health.

Dietary Bioactive Lipids: A Review on Absorption, Metabolism, and Health Properties

Dietary lipids are an indispensable source of energy and nutrition in human life. Numerous studies have shown that dietary bioactive lipids have many health benefits, including prevention or treatment of chronic diseases. The different chemical compositions and structural characteristics of bioactive lipids not only affect their digestion, absorption, and metabolism but also affect their health properties. In this review, the major dietary bioactive lipids (fatty acids, carotenoids, phytosterols, phenolic lipids, fat-soluble vitamins, and sphingomyelins) in foods are systematically summarized, from the aspects of composition, digestion, absorption, metabolism, source, structural characteristics, and their health properties. In particular, the relationship between the compositional and structural changes of bioactive lipids and their absorption and metabolism is discussed as well as their effect on health properties. This review provides a comprehensive summary toward health properties of dietary bioactive lipids.

Long-term dietary fiber intake and risk of chronic obstructive pulmonary disease: a prospective cohort study of women

PURPOSE

Until now, only two prospective cohort studies have investigated dietary fiber intake in relation to risk of chronic obstructive pulmonary disease (COPD), but neither examined long-term fiber intake. Both studies reported that total fiber intake was associated with decreased COPD risk; however, results for specific fiber sources were inconsistent. Thus, we prospectively evaluated the association between baseline and long-term intake of dietary fiber and COPD risk in a population-based prospective cohort of 35,339 Swedish women.

METHODS

Dietary fiber intake was assessed in 1987 and 1997 with a food frequency questionnaire. Cox proportional hazard regression models were used to estimate hazard ratios (HRs) and 95% confidence intervals (CIs).

RESULTS

During follow-up (2002-2014), 1557 COPD cases were identified via linkage to the Swedish National Patient Register. Long-term high dietary fiber intake (≥ 26.5 vs. < 17.6 g/day) was associated with a 30% (95% CI 17-41%) lower risk of COPD. For specific fiber sources, cereal (≥ 16.3 vs. < 9.4 g/day; HR 0.67, 95% CI 0.55-0.81) and fruit fiber (≥ 7.6 vs. < 2.6 g/day; HR 0.65, 95% CI 0.5-0.81), but not vegetable fiber intake (≥ 5.4 vs. < 2.2 g/day; HR 1.03, 95% CI 0.81-1.28) were associated with lower COPD risk. Current and ex-smokers with low long-term total fiber intake (< 17.6 g/day) compared to never smokers with high intake (≥ 26.5 g/day) had a 33-fold (95% CI 23.6-46.6) and tenfold (95% CI 7.0-16.3), respectively, higher risk of COPD.

CONCLUSIONS

Our findings indicate that high fiber intake is a modifiable lifestyle factor which may decrease COPD risk primarily in current and ex-smokers.

Flux analysis of the human proximal colon using anaerobic digestion model 1

The colon can be regarded as an anaerobic digestive compartment within the gastro intestinal tract (GIT). An in silico model simulating the fluxes in the human proximal colon was developed on basis of the anaerobic digestion model 1 (ADM1), which is traditionally used to model waste conversion to biogas. Model calibration was conducted using data from in vitro fermentation of the proximal colon (TIM-2), and, amongst others, supplemented with the bio kinetics of prebiotic galactooligosaccharides (GOS) fermentation. The impact of water and solutes absorption by the host was also included. Hydrolysis constants of carbohydrates and proteins were estimated based on total short chain fatty acids (SCFA) and ammonia production in vitro. Model validation was established using an independent dataset of a different in vitro model: an in vitro three-stage continuous culture system. The in silico model was shown to provide quantitative insight in the microbial community structure in terms of functional groups, and the substrate and product fluxes between these groups as well as the host, as a function of the substrate composition, pH and the solids residence time (SRT). The model confirms the experimental observation that methanogens are washed out at low pH or low SRT-values. The in silico model is proposed as useful tool in the design of experimental setups for in vitro experiments by giving insight in fermentation processes in the proximal human colon.

Sequential extraction of polysaccharides from enzymatically hydrolyzed okara byproduct: physicochemical properties and in vitro fermentability

Okara, a byproduct of soymilk production, has been upgraded through the use of an enzymatic treatment with Ultraflo L® to give a product (okara(ET)) which has a higher content of soluble dietary fibre and an enhanced ratio of soluble: insoluble fibre than is found in okara without treatment. Polysaccharides were isolated from okara(ET) by sequential extraction to yield soluble fractions in water (22%), CDTA (8.7%), alkali (37.7%) without and NaClO2 (9.1%) and the cellulosic residue represents a (22.5%). The physicochemical properties of okara(ET) were improved due to the enzymatic treatment: oil retention capacity (6.94g/g), water retention capacity (10.76g/g) and swelling capacity (13.85g/g) were higher than in okara that had not undergone enzymatic treatment. The gelation capacity (8%) and the cation exchange capacity (8.96mEq/kg) of okara(ET) were lower than that of other byproducts. Short chain fatty acid production during in vitro fermentation of okara(ET) by a pure culture of Bifidobacterium bifidus was mainly represented by acetic acid, followed by propionic and butyric acids. In addition, the decreases in pH and substrate consumption demonstrated the bifidogenic capacity of okara(ET).