Effect of dietary fiber on gut barrier function, gut microbiota, short‐chain fatty acids, inflammation, and clinical outcomes in critically ill patients: A systematic review and meta‐analysis

Abstract

Background: Although some studies have explored the relationships between dietary fiber (DF) supplement and gut barrier function, changes of gut microbiota, and clinical outcomes in critically ill patients, the results were not consistent. Objective:The purpose was to explore the effect of DF on gut barrier function, gut microbiota, short-chain fatty acids (SCFAs), inflammation, and clinical outcomes in critically ill patients. Methods:A search was performed through five databases from inception to July 12, 2021. Data were expressed as mean difference (MD) or odds ratio (OR) with CI.Results: Twenty-one studies involving 2084 critically ill patients were included.There was a significant reduction in intestinal permeability, demonstrated by lactulose/rhamnose ratio (MD, −0.04; 95% CI, −0.08 to −0.00; P = 0.03) on day 8, Creactive protein on day 14 (MD, −36.66; 95% CI, −44.40 to −28.93; P < 0.001) and duration of hospital stay (MD, −3.16; 95% CI, −5.82 to −0.49; P < 0.05) after DF supplement. There were no significant differences in SCFA levels, duration of mechanical ventilation, and mortality between two groups. However, subgroup analysis results indicated significant decreases in duration of hospital stay and risk of mortality were seen in the subgroups with a supplementary fiber dose ≥20 g/day (MD, −5.62 [95% CI, −8.04 to −3.21; P < 0.0001]; OR, 0.18 [95% CI, 0.06-0.57; P = 0.004]), as well as in the medical intensive care unit (MD, −4.77 [95% CI, −7.48 to −2.07; P < 0.01]; OR, 0.13 [95% CI, 0.03-0.65; P < 0.05]). Conclusions: DF may improve gut barrier function, modulate intestinal microbiota, decrease systemic inflammatory response, and advance clinical outcomes in critically ill patients.

The effect of fiber supplementation on the prevention of diarrhea in hospitalized patients receiving enteral nutrition: A meta-analysis of randomized controlled trials with the GRADE assessment

“…Our study results contradict a previous meta-analysis published in 2015, in which the benefit of fiber supplementation was observed only in non-critically ill patients and not in the ICU setting (34). Nevertheless, the current study results on the benefit of fiber supplementation in critically ill patients were consistent with a recent meta-analysis of dietary fiber in critical care patients published in 2021 (35). From our point of view, differences in the results between our meta-analysis and the prior meta-analysis by Kamarul Zaman et al (34) might be due to differences in the study inclusion criteria, as we only included randomized control studies, and seven RCTs conducted after 2015 were added to our recent meta-analysis.…”

Low-Grade Inflammation and Ultra-Processed Foods Consumption: A Review

“…In the E-DIITM, fiber is considered one of the factors that reduce diet-related inflammation. In previous studies, an adequate fiber intake was shown to be important in maintaining low CRP levels and in maintaining homeostasis of the gut microbiota [ 81 ]. A high UPF consumption can also lead to deficiencies of micronutrients considered to be anti-inflammatory factors in the diet, such as magnesium, vitamin C, vitamin D, zinc and niacin [ 82 ].…”

“…In fact, it has been suggested that a diet rich in fiber can decrease the systemic inflammatory response by improving the intestinal barrier function and modulating the intestinal microbiota [ 81 ]. This is because dietary fiber is essential for the formation of SCFAs, which are thought to play a key role in neuroimmunoendocrine regulation [ 106 ].…”

The importance of providing dietary fiber in medical and surgical critical care

“…The benefit from providing dietary fiber in critical illness is well documented in clinical studies. 10 Inflammatory markers including TNF-α, IL-6, and procalcitonin have been shown to be no different on admission to the ICU between patients who are critically ill and receiving a fiber-containing formula vs fiber-free formula but are significantly reduced in the group receiving the fibercontaining formula to significantly lower levels by the end of the second week. Serial levels of C-reactive protein show similar results, no different upon admission to the ICU between patients receiving a fiber-containing vs fiber-free formula but significantly lower levels by day 15 in the group receiving dietary fiber.…”