Dietary Fibre Intake in Relation to Asthma, Rhinitis and Lung Function Impairment-A Systematic Review of Observational Studies

Dietary carbohydrate types, genetic predisposition, and risk of adult-onset asthma: A longitudinal cohort study

We aimed to investigate the longitudinal associations among carbohydrate intake types, genetic predisposition, and risk adult onset asthma (AOA). A dataset of 96,487 participants from UK Biobank was included with 1830 cases of incident AOA during an average follow-up of 9.68 years. Participants with the highest intake of total sugar, free sugar, and fiber intake, as compared to those with the lowest intake of total sugar, free sugar, and fiber intake, showed a 17 % and 22 % increased risk of incident AOA, and a 16 % decreased risk of AOA, respectively. Substitution of 5 % energy from free sugars with 5 % energy from non-free sugars was associated with a significantly lower risk of AOA (Hazard Ratio [HR] = 0.93, 95 % Confidence Interval [CI]: 0.88, 0.99). Participants with high genetic risk and the highest intake of free sugar showed a 112 % (HR = 2.12, 95%CI: 1.68, 2.68) increased risk of incident AOA. Participants with low genetic risk and highest intake of fiber showed a 50 % (HR = 0.50, 95%CI: 0.39, 0.64) reduced risk of AOA. This study highlights the critical role of carbohydrate types in AOA prevention, with an emphasis on reduced free sugar, moderate non-free sugar, and increased fiber intake.

Application of Microbiome-Based Therapies in Chronic Respiratory Diseases

The application of microbiome-based therapies in various areas of human disease has recently increased. In chronic respiratory disease, microbiome-based clinical applications are considered compelling options due to the limitations of current treatments. The lung microbiome is ecologically dynamic and affected by various conditions, and dysbiosis is associated with disease severity, exacerbation, and phenotype as well as with chronic respiratory disease endotype. However, it is not easy to directly modulate the lung microbiome. Additionally, studies have shown that chronic respiratory diseases can be improved by modulating gut microbiome and administrating metabolites. Although the composition, diversity, and abundance of the microbiome between the gut and lung are considerably different, modulation of the gut microbiome could improve lung dysbiosis. The gut microbiome influences that of the lung via bacterial-derived components and metabolic degradation products, including short-chain fatty acids. This phenomenon might be associated with the cross-talk between the gut microbiome and lung, called gut-lung axis. There are multiple alternatives to modulate the gut microbiome, such as prebiotics, probiotics, and postbiotics ingestion and fecal material transplantation. Several studies have shown that high-fiber diets, for example, present beneficial effects through the production of short-chain fatty acids. Additionally, genetically modified probiotics to secrete some beneficial molecules might also be utilized to treat chronic respiratory diseases. Further studies on microbial modulation to regulate immunity and potentiate conventional pharmacotherapy will improve microbiome modulation techniques, which will develop as a new therapeutic area in chronic respiratory diseases.

Dietary fibre in relation to lung function and respiratory symptoms from childhood to adulthood

Background

Epidemiological studies suggest beneficial associations between dietary fibre intake, lung function and chronic respiratory symptoms in adults. Our aim was to investigate the association between dietary fibre intake in childhood and respiratory health up to adulthood.

Methods

The individual fibre intake of 1956 participants from the Swedish population-based birth cohort BAMSE was estimated from 98- and 107-item food frequency questionnaires at ages 8 and 16 years, respectively. At 8, 16 and 24 years, lung function was measured by spirometry. Respiratory symptoms (cough, mucus production, breathing difficulties/wheeze) were assessed by questionnaires, and airway inflammation by exhaled nitric oxide fraction (F_ENO) (≥25 ppb) at 24 years. Longitudinal associations with lung function were analysed by mixed-effects linear regression; associations with respiratory symptoms and airway inflammation were analysed by logistic regression, adjusting for potential confounders.

Results

There were no associations between fibre intake at 8 years, as total and from different sources, spirometry measurements and respiratory symptoms at 24 years. Higher fruit fibre intake tended to be inversely associated with airway inflammation at 24 years (OR 0.70, 95% CI 0.48-1.00), which became non-significant after exclusion of participants with food-related allergic symptoms (OR 0.74, 95% CI 0.49-1.10). No associations between fibre intake at 8 and 16 years as an updated lagged exposure and spirometry measurements up to 24 years were observed.

Conclusion

In this longitudinal study, we observed no consistent association between dietary fibre intake in childhood and lung function or respiratory symptoms up to adulthood. Further research on dietary fibre in relation to respiratory health across the life course is needed.

Allergic Inflammation: Effect of Propolis and Its Flavonoids

The incidence of allergic diseases and their complications are increasing worldwide. Today, people increasingly use natural products, which has been termed a "return to nature". Natural products with healing properties, especially those obtained from plants and bees, have been used in the prevention and treatment of numerous chronic diseases, including allergy and/or inflammation. Propolis is a multi-component resin rich in flavonoids, collected and transformed by honeybees from buds and plant wounds for the construction and adaptation of their nests. This article describes the current views regarding the possible mechanisms and multiple benefits of flavonoids in combating allergy and allergy-related complications. These benefits arise from flavonoid anti-allergic, anti-inflammatory, antioxidative, and wound healing activities and their effects on microbe-immune system interactions in developing host responses to different allergens. Finally, this article presents various aspects of allergy pathobiology and possible molecular approaches in their treatment. Possible mechanisms regarding the antiallergic action of propolis on the microbiota of the digestive and respiratory tracts and skin diseases as a method to selectively remove allergenic molecules by the process of bacterial biotransformation are also reported.

Diet and Health in Otolaryngology

Diet is essential to health and can modulate inflammatory markers, the microbiota, and epigenetic outcomes. Proper nutrition is also key to good postsurgical outcomes. Diet is challenging to study, resulting in a relative dearth of influential studies. There is substantial evidence regarding the benefits of a whole food plant-predominant diet on health and longevity, in general, but limited evidence regarding otolaryngologic disorders. Diet may be associated with the risk of head and neck cancer, hearing loss, laryngopharyngeal reflux, and sinonasal symptoms. Evidence, however, is heterogenous and often insufficient for treatment recommendations. Many opportunities exist for future research and expansion..

Dietary fibre in relation to asthma, allergic rhinitis and sensitization from childhood up to adulthood

Background

Dietary fibre may reduce the risk of allergy. Our aim was to investigate the association between fibre intake in childhood, asthma, allergic rhinitis and IgE sensitization up to adulthood.

Methods

The individual fibre intake of 2285 participants from the Swedish population‐based birth cohort BAMSE was estimated between 98‐ and 107‐item food frequency questionnaires at ages 8 and 16 years, respectively. At 8, 16 and 24 years, asthma and allergic rhinitis symptoms were assessed by questionnaires, and sensitization to common allergens by serum IgE. Longitudinal associations were analysed by generalized estimating equations, adjusting for potential confounders.

Results

An inverse overall association was indicated between fibre intake at 8 years and allergic rhinitis symptoms up to 24 years (OR per 5 g/d 0.86; 95% CI 0.77–0.96), particularly in combination with airborne (0.74; 0.62–0.89) and food (0.69; 0.54–0.88) allergen sensitization. Higher fibre intake was also associated with specific allergen sensitization, for example, birch (0.77; 0.67–0.88) and soy (0.68; 0.53–0.87). No association was observed with asthma. Regarding sources, fruit (0.79; 0.67–0.94) and other (potatoes, chips/popcorn, legumes, and nuts, 0.71; 0.50–0.99), but not cereal or vegetable fibre were associated with allergic rhinitis. In additional analyses, including long‐term fibre intake at 8 and 16 years, excluding participants with food‐related allergic symptoms to examine reverse causation, as well as adjusting for antioxidant intake, associations were attenuated and became non‐significant.

Conclusion

Higher fibre intake in mid‐childhood may be inversely associated with allergic rhinitis and sensitization to specific allergens up to adulthood. However, avoidance of food triggers of allergic symptoms in allergic rhinitis patients may contribute to the protective associations.

Soluble Dietary Fiber, One of the Most Important Nutrients for the Gut Microbiota

Dietary fiber is a widely recognized nutrient for human health. Previous studies proved that dietary fiber has significant implications for gastrointestinal health by regulating the gut microbiota. Moreover, mechanistic research showed that the physiological functions of different dietary fibers depend to a great extent on their physicochemical characteristics, one of which is solubility. Compared with insoluble dietary fiber, soluble dietary fiber can be easily accessed and metabolized by fiber-degrading microorganisms in the intestine and produce a series of beneficial and functional metabolites. In this review, we outlined the structures, characteristics, and physiological functions of soluble dietary fibers as important nutrients. We particularly focused on the effects of soluble dietary fiber on human health via regulating the gut microbiota and reviewed their effects on dietary and clinical interventions.