Fiber in diet shown to improve gut health measures for bedridden patients

In a recent study published in the journal Critical Care Explorations​, researchers presented the results of a randomized, controlled, open label pilot trial that assessed the microbial species makeup and the short chain fatty acid content of patients’ stools as well as other measures of comfort and health when administering a fiber-containing nutrition product versus one with no fiber.  The authors were all associated with Presbyterian Hospital, Columbia University Medical Center, New York, NY.

Abbott products used in trial

For their test materials, the researchers used two products to administer to 20 patients who received enteral nutrition, both made by Abbott, which had no involvement in the study.  The products were Abbott Promote, which provided 14.3 grams of soy and oat fiber in a serving, and a version of Promote with no fiber.  The researchers chose the products based on their identical nature, with the same number of calories per serving, except for the fiber difference.

The subjects were receiving broad spectrum antibiotics to treat sepsis.  They received enteral nutrition using the Abbott products.  The care givers were instructed to stay with the Promote nutrition as long as possible, but not to restrict the addition of ad lib nutrition when the patients were ready to transition to oral nutrition. 

The actual average difference in fiber intake between the two groups ended up being about 11 grams/day, which was lower than the researchers said was ideal.  The subjects’ gut microbiome makeup was assessed via rectal swabs at day three.  The study was designed to follow patients at intervals up to 30 days, hospital discharge, or death.

Fiber shows changes in gut

The main outcome was to check for the relative populations of SCFA-producing bacteria in the swabs. Secondary outcomes included actual SFCA content in the stools and stool consistency and frequency.

The patients receiving the fiber showed a 61% increase in SFCA-producing bacteria, while the no fiber group saw a 41% decrease in those species.  The actual SFCA content in stools tracked those differences closely, they said.  But because of the small size of the trial the researchers said even these large disparities did not amount to statistical significance.

Having an abundance of SFCA in the gut has been shown to have many beneficial effects​​.  These including maintaining the health and integrity of the epithelium, playing a role in glucose homeostasis and lipid metabolism and may even play a key role in appetite regulation and thus obesity.  Past studies have found that some probiotics, which are themselves SFCA producing bacteria, can help ameliorate the diarrhea often associated with antibiotic treatment.

One reason why some clinicians have shied away from fiber-containing products for the feeding of patients in this setting has been the belief that with patients being in a quiescent state and the well-known gut disruptions antibiotics can cause,  administering a high level of fiber would result in uncomfortable or even dangerous symptoms in the gut, such as blockages.  The researchers did not observe any of that in this trial.

More SFCA production, and better stool consistency

On the contrary, the fiber group had firmer stools and a reduced stool frequency of about one a day. This could increase patient comfort and hygiene, the researchers said, as well as make the patients easier to care for.

Beyond the small size, the researchers said another limitation of their study was the homogenous nature of the study material.  They said they planned future, larger-scale studies including just one fiber type, such as inulin.  And they said their data could provide the basis for future studies that might look into whether the increased SCFA levels resulted in better clincal outcomes.

Source​: Critical Care Explorations​​​
doi: 10.1097/CCE.0000000000000135
Impact of Fiber-Based Enteral Nutrition on the Gut Microbiome of ICU Patients Receiving Broad-Spectrum Antibiotics: A Randomized Pilot Trial
Authors: Freedburg DE, et al.