Evaluating efficacy of probiotics combined with prebiotics in small intestinal bacterial overgrowth (SIBO) in subclinical hypothyroidism (SCH) in the second trimester. We collected data from 78 pregnant women with SCH (SCH group) and 74 normal pregnant women (control group) in second trimester, compare the differences in high sensitivity C-reactive protein (hsCRP), result of lactulose methane-hydrogen breath test and gastrointestinal symptoms assessed by GSRS scale between two groups. In SCH group, 32 patients with SIBO were selected as intervention group. Treatment with probiotics + prebiotics for 21 days; The differences of lipid metabolism, hsCRP, thyroid function level, methane-hydrogen breath test results and GSRS scores before and after treatment were compared to evaluate the therapeutic effect. (1) The positive rate of SIBO and methane, hsCRP levels in SCH group were higher than those in control group (P < 0.05), the total score of GSRS scale, mean score of indigestion syndrome, and constipation syndrome in SCH group were higher (P < 0.05). (2) The mean abundance of hydrogen and methane were higher in SCH group. (3) After treatment, serum levels of thyrotropin(TSH), total cholesterol(TC), triglyceride(TG), low-density lipoprotein (LDL), and hsCRP in intervention group were decreased, and high-density lipoprotein (HDL) was increased compared with before treatment (P < 0.05). (4) After treatment, methane positive rate, total score of GSRS scale, mean score of diarrhea syndrome, dyspepsia syndrome, and constipation syndrome were decreased (P < 0.05). (5) The average abundance of methane and hydrogen were lower. Probiotics combined with prebiotics are effective in the treatment of SIBO in pregnant SCH patients.Clinical Trial Registration Number: ChiCTR1900026326.

UNASSIGNED: Several systematic reviews and meta-analyses have investigated the effect of levothyroxine (LT4) therapy in pregnant women with subclinical hypothyroidism (SCH). However, all these studies have clinical or methodological problems (such as adopting the old 2011 American Thyroid Association [ATA] diagnostic criteria, directly combining randomized controlled trials [RCTs] and cohort studies for meta-analysis, and so on), and cannot provide accurate and satisfactory results. Thus, we performed this updated systematic review, meta-analysis and trial sequential analysis (TSA) to assess the effect of LT4 therapy in pregnant women with SCH, with the goal of providing more accurate and reliable evidence for clinical practice.
UNASSIGNED: We searched nine databases from inception to February 2022. The search strategy targeted the RCTs and cohort studies on pregnancy, neonatal and childhood outcomes following LT4 treatment in pregnant women with SCH based on the new 2017 ATA diagnostic criteria. We performed meta-analyses of RCTs and cohort studies separately, and further performed meta-analyses by excluding studies with high risk of bias. TSA was performed to test whether the current evidence was sufficient, and the quality of evidence was evaluated using the GRADE method.
UNASSIGNED: A total of 9 RCTs and 13 cohort studies comprising 11273 pregnant women with SCH were included. There were no statistically significant differences between LT4 group and control group in all primary and secondary outcomes, such as preterm delivery (RR=0.46, 95%CI: 0.19-1.09, P=0.08, I2 = 65%), miscarriage (RR=0.36, 95%CI: 0.13-1.03, P=0.06, I2 = 38%), gestational hypertension (RR=0.91, 95%CI: 0.58-1.43, P=0.69, I2 = 0%), preeclampsia (RR=1.10, 95%CI: 0.61-1.97, P=0.76, I2 = 0%), gestational diabetes (RR=0.80, 95%CI: 0.51-1.25, P=0.32, I2 = 34%), and so on. TSA showed that the results for all outcomes were insufficient and inconclusive. According to GRADE, the evidences for four outcomes (miscarriage, gestational hypertension, gestational diabetes, and small for gestational age) were rated as moderate quality, while the evidences for the other outcomes were rated as low or very low quality.
UNASSIGNED: Unlike previous systematic reviews and meta-analyses, our study found no evidence of benefit of LT4 therapy on pregnancy, neonatal and childhood outcomes in pregnant women with SCH.
UNASSIGNED: PROSPERO, https://www.crd.york.ac.uk/prospero/display_record.php?ID=CRD42022321937, identifier CRD42022321937.

Pregnant women are at high risk of developing subclinical hypothyroidism (SCH), and anti-thyroid peroxidase antibody (TPOAb) positivity can further inhibit thyroxine synthesis. Emerging evidence indicates that intestinal flora can modulate metabolic and immune homeostasis. The characteristics of intestinal flora of TPOAb-positive women with SCH in their second trimester of pregnancy have not been reported. This single-center prospective observational cohort study investigated gut microbial composition and metabolic function using sequencing of the 16S rRNA gene in fecal samples from 75 TPOAb-positive women with SCH and 90 TPOAb-negative women with SCH during their second trimester of pregnancy. Women were treated with no levothyroxine (LT4), low-dose LT4 (≤50ug/d), or high-dose LT4 (>50ug/d). Taxonomic analysis showed Firmicutes and Bacteroidetes were the dominant phyla, followed by Actinobacteria and Proteobacteria. Faecalibacterium, Bacteroides, Prevotella 9, Bifidobacterium, Subdoligranulum, Lachnospira, and Megamonas were the predominant genera. The intestinal flora of TPOAb-positive women with SCH who received no LT4 was characterized by bacterial amplicon sequence variants (ASVs)/operational taxonomic units (OTUs) enriched in the genus Subdoligranulum. The intestinal flora of TPOAb-positive women with SCH who received low-dose or high-dose LT4 were characterized by bacterial ASVs/OTUs depleted of the species Ruminococcus sp._or Bacteroides massiliensis, respectively. A total of 19 metabolic functions of intestinal flora, mainly involving lipid and amino acid metabolism, discriminated TPOAb-positive and TPOAb-negative women with SCH. Our study suggests that there are differences in the composition and metabolic function of intestinal flora of TPOAb-positive and TPOAb-negative women with SCH treated with different doses of LT4 in the second trimester of pregnancy. The findings provide insight into intestinal flora as novel targets for the treatment of TPOAb-positive women with SCH during pregnancy.