title: Effect of lactose on gut microbiota and metabolome of infants with cow's milk allergy.
abstract: Allergic infants have an unusual gastrointestinal microbiota with low numbers of Bifidobacterium/Lactobacilli and high levels of Clostridium, staphylococci and Escherichia coli. Hydrolyzed formula used to treat these infants is deprived of lactose that instead may influence the gut microbial composition. The aim of the present study is to investigate the influence of lactose on the composition of the gut microbiota and metabolome of infants with cow's milk allergy. Infants prospectively enrolled received an extensively hydrolyzed formula with no lactose for 2 months followed by an identical lactose-containing formula for an additional 2 months. Healthy, age-gender-matched infants were used as controls. The following determinations were performed before and after the introduction of lactose in the diet: enumeration of cells present in the feces using FISH, counts of viable bacterial cells and gas-chromatography mass spectrometry/solid-phase microextraction analysis. The addition of lactose to the diet significantly increases the counts of Bifidobacteria and lactic acid bacteria (p < 0.01), decreases that of Bacteroides/clostridia (p < 0.05) reaching counts found in healthy controls; lactose significantly increases the concentration of total short-chain fatty acids (p < 0.05). The addition of lactose to an extensively hydrolyzed formula is able to positively modulate the composition of gut microbiota by increasing the total fecal counts of Lactobacillus/Bifidobacteria and decreasing that of Bacteroides/Clostridia. The positive effect is completed by the increase of median concentration of short chain fatty acids, especially for acetic and butyric acids demonstrated by the metabolomic analysis.
authors.affiliation: Department of Pediatrics, University of Bari Aldo Moro, Bari, Italy. rfrancavilla@me.com
authors.forename: Ruggiero
authors.initials: R
authors.lastname: Francavilla
authors.forename: Maria
authors.initials: M
authors.lastname: Calasso
authors.forename: Laura
authors.initials: L
authors.lastname: Calace
authors.forename: Sonya
authors.initials: S
authors.lastname: Siragusa
authors.forename: Maurice
authors.initials: M
authors.lastname: Ndagijimana
authors.forename: Pamela
authors.initials: P
authors.lastname: Vernocchi
authors.forename: Luigia
authors.initials: L
authors.lastname: Brunetti
authors.forename: Giuseppe
authors.initials: G
authors.lastname: Mancino
authors.forename: Giuseppe
authors.initials: G
authors.lastname: Tedeschi
authors.forename: Elisabetta
authors.initials: E
authors.lastname: Guerzoni
authors.forename: Flavia
authors.initials: F
authors.lastname: Indrio
authors.forename: Luca
authors.initials: L
authors.lastname: Laghi
authors.forename: Vito L
authors.initials: VL
authors.lastname: Miniello
authors.forename: Marco
authors.initials: M
authors.lastname: Gobbetti
authors.forename: Maria
authors.initials: M
authors.lastname: De Angelis
mesh_terms: D000818:Animals; D002417:Cattle; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007223:Infant; D041943:Infant Formula / Q000008:administration & dosage* / Q000378:metabolism; D007422:Intestines / Q000382:microbiology*; D007785:Lactose / Q000008:administration & dosage* / Q000378:metabolism; D008297:Male; D055442:Metabolome; D054892:Metagenome; D008892:Milk / Q000276:immunology / Q000378:metabolism; D016269:Milk Hypersensitivity / Q000276:immunology / Q000382:microbiology*; D011446:Prospective Studies
chemical_list: D007785:Lactose