Breastfeeding Affects Concentration of Faecal Short Chain Fatty Acids During the First Year of Life: Results of the Systematic Review and Meta-Analysis

Abstract

Short chain fatty acids (SCFAs) are important metabolites of the gut microbiota. It has been shown that the microbiota and its metabolic activity in children are highly influenced by the type of diet and age. Our aim was to analyse the concentration of fecal SCFAs over two years of life and to evaluate the influence of feeding method on the content of these compounds in feces. We searched PubMed/MEDLINE/Embase/Ebsco/Cinahl/Web of Science from the database inception to 02/23/2021 without language restriction for observational studies that included an analysis of the concentration of fecal SCFAs in healthy children up to 3 years of age. The primary outcome measures-mean concentrations-were calculated. We performed a random-effects meta-analysis of outcomes for which ≥2 studies provided data. A subgroup analysis was related to the type of feeding (breast milk vs. formula vs. mixed feeding) and the time of analysis (time after birth). The initial search yielded 536 hits. We reviewed 79 full-text articles and finally included 41 studies (n = 2,457 SCFA analyses) in the meta-analysis. We found that concentrations of propionate and butyrate differed significantly in breastfed infants with respect to time after birth. In infants artificially fed up to 1 month of age, the concentration of propionic acid, butyric acid, and all other SCFAs is higher, and acetic acid is lower. At 1–3 months of age, a higher concentration of only propionic acid was observed. At the age of 3–6 months, artificial feeding leads to a higher concentration of butyric acid and the sum of SCFAs. We concluded that the type of feeding influences the content of SCFAs in feces in the first months of life. However, there is a need for long-term evaluation of the impact of the observed differences on health later in life and for standardization of analytical methods and procedures for the study of SCFAs in young children. These data will be of great help to other researchers in analyzing the relationships between fecal SCFAs and various physiologic and pathologic conditions in early life and possibly their impact on health in adulthood.

Analysis of Fecal Short-Chain Fatty Acids (SCFAs) in Healthy Children during the First Two Years of Life: An Observational Prospective Cohort Study

“…Acetic acid concentration increased significantly only up to 1 month after birth and no significant increase was seen until the end of the study period ( Table 3 and Figure 2 ). The measured concentrations are somehow similar to analyses by other authors [ 18 ]. Correlation analyses and effect sizes are shown in Supplementary Tables S1–S5 .…”

“…In the multivariable analysis, this factor was, however, only significant regarding linear butyrate at 12 months. These observations are partially confirmed by the results of a recently published meta-analysis from our group [ 18 ] and might result from a difference in microbiota composition between breast- and formula-fed children [ 34 , 35 , 36 , 37 , 38 , 39 ]. Additionally, a meta-analysis of 1825 stool samples from 684 infants found that microbiome diversity, maturity, the relative abundance of Bacteroidetes and Firmicutes and the predicted pathways of carbohydrate metabolism were greater in formula-fed infants [ 40 ].…”

“…We, however, analyzed the effect size, and the obtained results usually had average effects. In addition, the size of our cohort was comparable to the number of children studied in other clinical trials dealing with similar topics [ 18 ]. At last, due to number of milk formulas present in the market, such information was not provided.…”

“…Importantly, it was demonstrated that acetic and butyric acids might play a role in bacterial gene expression as evidenced in Salmonella and Escherichia . Propionate can be utilized by many cells, including epithelial ones, and, once it enters the liver, is a substrate for gluconeogenesis [ 18 ].…”

Analysis of correlations between gut microbiota, stool short chain fatty acids, calprotectin and cardiometabolic risk factors in postmenopausal women with obesity: a cross-sectional study

“…Another factor that may influence the nature of the correlation between bacterial abundance and SCFA is a significant limitation of faecal SCFA analysis. The content of SCFA in the stool results from the production of these compounds by the intestinal bacteria, their absorption and their expenditure in situ in the gastrointestinal tract [ 80 ]. Faecal SCFA excretion results may not correspond to those measured in blood, which may better reflect SCFA production and absorption.…”