Three new studies: asthma shots by the clock, gut genes read from stool and sugar spikes in children

THREE NEW PAPERS on medRxiv, a website where researchers post studies before publication, deal with the clock, the gut and the blood sugar of children.

Asthma injections by the clock

People with allergic asthma react to dust or pollen because their immune system makes too much of an antibody called IgE. IgE sits on mast cells, immune cells in the airways that release chemicals which narrow the breathing tubes. Omalizumab is an injected antibody that stops IgE from binding to those cells. Asthma also follows a daily rhythm, and a 2021 study of 17 patients in PNAS found lung function at its lowest around 4 am.

On November 2nd Ayobami Akenroye of Brigham and Women's Hospital in Boston and Jeffrey Haspel of Washington University School of Medicine in St. Louis, the lead and senior authors, posted a preprint, a study not yet peer reviewed by outside scientists, analyzing 153 patients who began omalizumab in the Mass General Brigham hospital system. Of these, 74 had their first dose in the morning and 79 in the afternoon. A good response meant at least halving asthma attacks over the next year. The predicted chance of that was 76.3% for afternoon starters and 38.2% for morning starters. Attacks per patient fell from 1.33 a year to 0.69 in the afternoon group and from 1.26 to 1.22 in the morning group. In mice housed on shifted light schedules, an anti-IgE treatment worked best late in the animals' active period, which the authors liken to the human afternoon.

The study used hospital records rather than a trial, so unmeasured differences between the groups could explain the result. The response analysis included only patients who had at least one attack in the year before treatment, and 73 of them had complete records. The timing of the second to fourth doses showed no significant link to response in the main analysis, though a separate analysis linked an afternoon fourth dose to fewer attacks. The authors call for randomized trials before anyone changes appointment times.

Reading the gut's genes from stool

The lining of the gut constantly sheds cells into the bowel, and those cells carry messenger RNA, the short-lived copies of genes that a cell is using at that moment. Reading that RNA from stool could show what the gut lining is doing without a colonoscopy. It is hard because most RNA in stool comes from bacteria and human RNA breaks down quickly.

Wenying Pan of Guangdong Jiyin Biotech in Shenzhen, the lead author, and Min Li of Renji Hospital, Shanghai Jiao Tong University School of Medicine, the senior author, posted a method on November 2nd in a preprint that has not yet been peer reviewed. Across 285 stool samples it detected a median of 6,300 human genes per sample. A 2025 method from another group detected a median of 1,745. The samples came from 77 people with normal results, 63 with precancerous growths, 55 with colorectal cancer and 90 with inflammatory bowel disease, a long-term inflammation of the gut. A computer model sorted cancer, bowel disease and normal samples correctly 87% of the time. In bowel disease, a score built from 15 genes active in neutrophils, a type of white blood cell, tracked inflammation seen by camera more closely than calprotectin, the standard stool test, in two groups of patients (0.66 against 0.36 in 27 samples and 0.75 against 0.11 in 36, on a scale where 1 is perfect agreement).

The method caught only 42% of precancerous growths at a setting that wrongly flagged one in ten normal samples. All accuracy figures were checked by repeatedly holding back part of the same samples, not on a new group of patients. The test is not on sale, and the data are available only on request through the company.

Brief sugar spikes in children

Type 1 diabetes is a disease in which the body stops making insulin, the hormone that moves sugar from the blood into cells. Many children with it wear a small sensor on the arm that measures sugar under the skin every five minutes. Doctors summarize those readings as time in range, the share of the day spent between 70 and 180 mg/dL, and an international consensus sets the target at above 70%.

Guillaume Deside and Philippe Lysy of UCLouvain in Belgium, the lead and senior authors, posted a study on October 30th with Zain Syed and Laura Symul, as a preprint that has not yet been peer reviewed. They examined sensor records from 135 children and young people at one Brussels hospital. Of 15,556 episodes of high sugar, 2,874 (18.5%) were brief daytime spikes lasting 10 to 60 minutes with normal readings on either side. When the researchers removed those spikes from the records, daytime time in range went up by 1.74 percentage points. Two patients had almost identical reports, with 17.2% and 17.1% of their time above range, yet one had 59 spikes and the other 19.

The study comes from one hospital and uses records only. It had no logs of meals or insulin doses, so the idea that snacks or late insulin cause the spikes remains a hypothesis. The redrawn readings join each spike's low points with a straight line, which is an estimate rather than an observation. The authors suggest checking for such spikes before increasing insulin, and they call for studies with meal and insulin data to test whether that reduces overtreatment.