ArticleThe American journal of gastroenterology2026
Distinct Clinical Phenotypes in Lactase Nonpersistence: Symptomatic, Asymptomatic, and Gassy-Asymptomatic.
Article in The American journal of gastroenterology, 2026. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Not yet cited in PubMed.
What it found
Each row is one number read from the abstract, on the scale the paper reported it, with its interval. Left of the dashed line favours the treatment, right favours the comparator. Under each row is the sentence it came from. New to these charts? A ten-minute tutorial.
The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.
The trial behind it
Trials whose registry record cites this paper, or whose number appears in the abstract. A trial that started after this paper was published is citing it as background, not reporting it.
Neither the registry nor the abstract names a trial number. If this is a trial report, that itself is worth knowing.
Who cites it
0 citing papers in PubMed.
No citing paper in PubMed yet.
Corrections and comments
PubMed lists nothing against this paper. Absence here is not a guarantee, only a check that was made.
Authors and funding
6 authors.
Funding
Abstract
introductionLactase deficiency allows undigested lactose to reach the colon, where fermentation triggers gastrointestinal symptoms. Although lactase persistence (LP) vs non-persistence (LNP) is genetically defined, many LNP individuals are symptoms-free, suggesting additional determinants of the phenotype. We aimed to define clinically relevant LNP subgroups and examine microbiome features that differ among them.
methodsIn 146 healthy adults, LP-associated single nucleotide polymorphisms were genotyped and a standardized 25 g lactose load was administered. Breath hydrogen, methane, blood glucose, and symptom scores were collected over 3 hours. Microbiome composition (n = 60) was profiled by 16S-rRNA sequencing of stool samples.
resultsAmong LNP individuals (116/146, 79%), 3 distinct phenotypes emerged: Symptomatic (35/116, 30%), who produced hydrogen and reported symptoms; Gassy Asymptomatic (67/116, 58%), who produced hydrogen without symptoms; and Asymptomatic (14/116, 12%), who neither produced hydrogen nor had symptoms. All LNP subgroups showed similarly low blood glucose elevations after lactose load compared with LP. A novel metric, peak hydrogen production rate (ppm/hour), improved correlation with symptom severity (R = 0.49) vs the conventional hydrogen peak (R = 0.34). Microbiome analyses revealed higher abundances of certain genera such as Lactobacillus and Megasphaera in asymptomatic LNP subgroups, suggesting possible microbial contributions to the absence of symptoms. DISCUSSION: Seventy percent of genetically LNP adults tolerate lactose without symptoms. Classifying LNP individuals into distinct subgroups and incorporating hydrogen production rate into breath-test interpretation may enhance diagnostic precision, prevent unnecessary dietary restrictions, and generate new hypotheses linking fermentation kinetics and symptoms. Microbiome associations remain correlative and warrant functional validation in larger, controlled studies.
Indexed as
Identifiers
What OpenQuestion holds
Registered trials
Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the OpenQuestion graph.