BACKGROUND:As coronavirus disease 2019 (COVID-19) is integrated into existing infectious disease control programs, it is important to understand the comparative clinical impact of COVID-19 and other respiratory diseases. METHODS:We conducted a retrospective cohort study of patients with symptomatic healthcare-associated COVID-19 or influenza reported to the nationwide, hospital-based surveillance system in Switzerland. Included patients were adults (aged ≥18 years) hospitalized for ≥3 days in tertiary care and large regional hospitals. Patients had COVID-19 symptoms and a real-time polymerase chain reaction-confirmed severe acute respiratory syndrome coronavirus 2 infection ≥3 days after hospital admission between 1 February 2022 and 30 April 2023, or influenza symptoms and a real-time polymerase chain reaction-confirmed influenza A or B infection ≥3 days after hospital admission between 1 November 2018 and 30 April 2023. Primary and secondary outcomes were 30-day in-hospital mortality and admission to intensive care unit, respectively. Cox regression (Fine-Gray model) was used to account for time dependency and competing events, with inverse probability weighting to adjust for confounding. RESULTS:We included 2901 patients with symptomatic, healthcare-associated COVID-19 (Omicron) and 868 patients with symptomatic, healthcare-associated influenza from 9 hospitals. We found a similar case fatality ratio between healthcare-associated COVID-19 (Omicron) (6.2%) and healthcare-associated influenza (6.1%) patients; after adjustment, patients had a comparable subdistribution hazard ratio for 30-day in-hospital mortality (0.91; 95% confidence interval, .67-1.24). A similar proportion of patients were admitted to the intensive care unit (2.4% COVID-19; 2.6% influenza). CONCLUSIONS:COVID-19 and influenza continue to cause severe disease among hospitalized patients. Our results suggest that in-hospital mortality risk of healthcare-associated COVID-19 (Omicron) and healthcare-associated influenza are comparable.
Bifidobacteria are among the most dominant members of the human gut microbiota throughout life and are associated with host health. Multiple Bifidobacterium species have been isolated from human faeces, with species composition differing according to host age and between individuals. This species- and subspecies-level diversity reflects adaptation to host niches. Bifidobacterium catenulatum currently comprises two subspecies catenulatum and kashiwanohense, which appear to exhibit different ecological adaptations. Our previous study suggested undefined lineages closely related to B. catenulatum. In this study, we investigated these lineages through comparative genomic and phylogenetic analyses of 43 strains, including new isolates from human faeces.Phylogenetic reconstructions based on 16S rRNA gene sequences, multilocus sequence analysis, average nucleotide identity (ANI) and core-gene alignments consistently supported the delineation of two distinct taxa. The first group, consisting of 15 strains, exhibited ANI values of ≥96.41% among themselves but ≤94.79% compared with the known subspecies of B. catenulatum, confirming its classification as a novel species, which was recently validated as Bifidobacterium hominis. The second group, comprising four strains, showed ANI values ranging from 94.38 to 95.65% compared to the existing subspecies of B. catenulatum, indicating that they belong to the same species. However, phylogenetic analyses and distinct substrate utilization profiles supported their designation as a novel subspecies, B. catenulatum subsp. puerorum subsp. nov.Comparative genomic analyses revealed key differences in genes associated with gut adaptation. B. catenulatum subsp. puerorum harboured genes involved in human milk oligosaccharide (HMO) and urea metabolism, consistent with its isolation from infant faeces. In contrast, B. hominis exhibited strain-dependent variation in genes for HMO and xylooligosaccharide utilization. Phenotypic analyses supported these distinctions, including unique inulin utilization by B. catenulatum subsp. puerorum. Based on these findings, we characterized the two clades and propose the novel subspecies B. catenulatum subspecies puerorum, with type strain YIT 11099T (=JCM 37523T=DSM 118686T).
Background Dairy product consumption is associated with a lower risk of all-cause mortality. However, the evidence regarding probiotic-fermented milk products remains unclear. This study examined the association between the intake of fermented milk products containing lactic acid bacteria, including Lacticaseibacillus paracasei strain Shirota (LcS), and all-cause mortality. Methods A total of 1,280 community-dwelling Japanese aged ≥65 years (519 men, 761 women; mean age 73.5 years) were included in the analyses. Participants were categorized in two groups based on the retrospectively recalled intake frequency of fermented milk products (<3 or ≥3 days/week) over 5- and 10-year periods. All-cause mortality risk was evaluated using Cox proportional hazards regression analyses in the full sample and propensity score-matched subsamples. Results During the 9.3-year follow-up period (112.05 months), deaths occurred in 147 men (28.3%) and 114 women (15.0%). Among men, consumption of fermented milk products containing LcS for ≥3 days/week over five years was significantly associated with a lower risk of all-cause mortality in both full sample analysis (hazard ratio [HR] 0.648, 95% confidence interval [CI] 0.438–0.958, p = 0.030) and matched analysis (HR 0.640, 95% CI 0.434–0.943, p = 0.024), compared with those consuming <3 days/week. Similar associations were observed for overall fermented milk products, including the LcS products. No associations were found among women for either LcS or overall fermented milk products. Conclusion Habitual intake of fermented milk products containing LcS was associated with a lower risk of all-cause mortality in older Japanese men.
OBJECTIVES:To investigate the effects of Bifidobacterium breve strain Yakult (BbrY) administration immediately after birth on the microbiome of cesarean-born full-term infants with an immature microbiota at birth. METHODS:This single-center, placebo-controlled, randomized, double-blind, parallel-group intervention study included healthy, full-term Japanese infants born via planned cesarean section. Infants were administered either BbrY or placebo for the first month of life. The primary endpoint was the early establishment of a Bifidobacterium-dominant microbiome. RESULTS:This study included 26 infants (14 in the BbrY group and 12 in the placebo group). Compared with the placebo group, the BbrY group showed significantly increased detection rates and counts of BbrY from day three to six months post-birth, with the level and proportion of Bifidobacterium and Bifidobacteriaceae remaining elevated until one month post-birth. Total bacterial counts and total organic acid concentrations, including acetic and lactic acids, were significantly higher in the BbrY group until the sixth day of life, concomitant with a decrease in fecal pH. At nine months, the BbrY group exhibited a significantly higher body weight than the placebo group, and the Kaup index remained within the normal range at six and nine months. CONCLUSIONS:BbrY supplementation immediately after birth facilitated the early establishment of a Bifidobacterium-dominant microbiome and contributed to intestinal acidification in cesarean-born infants, indicating BbrY administration may support normal growth patterns during infancy.
