Mendelian randomization study of causal link from gut microbiota to colorectal cancer.

Recent studies have shown the relevance of gut microbiota in the occurrence and development of colorectal cancer (CRC), but the causal relationship remains unclear in the human population. The present study aims to assess the causal relationship from the gut microbiota to CRC and to identify specific causal microbe taxa via genome-wide association study (GWAS) summary statistics based two-sample Mendelian randomization (MR) analyses. Microbiome GWAS (MGWAS) in the TwinsUK 1,126 twin pairs was used as discovery exposure sample, and MGWAS in 1,812 northern German participants was used as replication exposure sample. GWAS of CRC in 387,156 participants from the UK Biobank (UKB) was used as the outcome sample. Bacteria were grouped into taxa features at both family and genus levels. In the discovery sample, a total of 30 bacteria features including 15 families and 15 genera were analyzed. Five features, including 2 families (Verrucomicrobiaceae and Enterobacteriaceae) and 3 genera (Akkermansia, Blautia, and Ruminococcus), were nominally significant. In the replication sample, the genus Blautia (discovery beta=-0.01, P = 0.04) was successfully replicated (replication beta=-0.18, P = 0.01) with consistent effect direction. Our findings identified genus Blautia that was causally associated with CRC, thus offering novel insights into the microbiota-mediated CRC development mechanism.

Mendelian randomization analysis identified causal Association of Childhood Obesity with adult major depressive disorder.

BACKGROUND: Childhood obesity is associated with adult major depressive disorder (MDD), but their causality is not clear. METHODS: We performed a two-sample Mendelian randomization (MR) analysis to explore the causality of childhood body mass index (BMI) and childhood obesity on MDD, followed by a multivariable MR (MVMR) analysis to investigate the potential role of adult BMI in mediating such effect. We accessed genome-wide association summary statistics of childhood BMI, childhood obesity, adult BMI and adult MDD from the Early Growth Genetics consortium (nBMI  = 47 541, nobesity  = 24 160), the Genetic Investigation of Anthropometric Traits consortium (nadult_BMI  = âˆ¼700 000) and the Psychiatric Genomics consortium (nMDD  = 500 199), respectively. The MR-PRESSO test was performed to remove SNPs with potential pleiotropic effect. The MR analysis was performed by inverse-variance weighted test. Further sensitivity analyses, including the MR-Egger intercept test and leave-one-out analysis, were performed to evaluate the reliability of the results. RESULTS: Our study found that childhood obesity might increase the odds of developing MDD in adults (OR = 1.03, 95% CI: 1.01-1.06, p = 2.6 × 10-3 ). Children with higher BMI were more likely to develop MDD in adulthood, with an OR of 1.12 per standard deviation score (SDS) increase in BMI (95% CI: 1.07-1.17, p = 4.4 × 10-7 ). Sensitivity analyses verified the reliability of the causality between childhood BMI/obesity and MDD. Further MVMR results revealed that the impact of childhood BMI on MDD risk was predominantly mediated by adult BMI. CONCLUSION: Our findings provided evidence of a causal relationship between childhood BMI/obesity and adult MDD, thus providing new insights into the prevention of MDD.

Mendelian Randomization Analysis Reveals Causal Effects of Plasma Proteome on Body Composition Traits.

CONTEXT: Observational studies have demonstrated associations between plasma proteins and obesity, but evidence of causal relationship remains to be studied. OBJECTIVE: We aimed to evaluate the causal relationship between plasma proteins and body composition. METHODS: We conducted a 2-sample Mendelian randomization (MR) analysis based on the genome-wide association study (GWAS) summary statistics of 23 body composition traits and 2656 plasma proteins. We then performed hierarchical cluster analysis to evaluate the structure and pattern of the identified causal associations, and we performed gene ontology enrichment analysis to explore the functional relevance of the identified proteins. RESULTS: We identified 430 putatively causal effects of 96 plasma proteins on 22 body composition traits (except obesity status) with strong MR evidence (P < 2.53 × 10 - 6, at a Bonferroni-corrected threshold). The top 3 causal associations are follistatin (FST) on trunk fat-free mass (Beta = -0.63, SE = 0.04, P = 2.00 × 10-63), insulin-like growth factor-binding protein 1 (IGFBP1) on trunk fat-free mass (Beta = -0.54, SE = 0.03, P = 1.79 × 10-57) and r-spondin-3 (RSPO3) on WHR (waist circumference/hip circumference) (Beta = 0.01, SE = 4.47 × 10-4, P = 5.45 × 10-60), respectively. Further clustering analysis and pathway analysis demonstrated that the pattern of causal effect to fat mass and fat-free mass may be different. CONCLUSION: Our findings may provide evidence for causal relationships from plasma proteins to various body composition traits and provide basis for further targeted functional studies.

Joint Genome-Wide Association Analyses Identified 49 Novel Loci For Age at Natural Menopause.

BACKGROUND: Age at natural menopause (ANM) is an important index for women's health. Either early or late ANM is associated with a series of adverse outcomes later in life. Despite being an inheritable trait, its genetic determinant has not yet been fully understood. METHODS: Aiming to better characterize the genetic architecture of ANM, we conducted genome-wide association study (GWAS) meta-analyses in European-specific as well as trans-ancestry samples by using GWAS summary statistics from the following 3 large studies: the Reproductive Genetics Consortium (ReproGen; N = 69 626), the UK Biobank cohort (UKBB; N = 111 593) and the BioBank Japan Project (BBJ; N = 43 861), followed by a series of bioinformatical assessments and functional annotations. RESULTS: By integrating the summary statistics from the 3 GWAS of up to 225 200 participants, this largest meta-analysis identified 49 novel loci and 3 secondary signals that were associated with ANM at the genome-wide significance level (P < 5 × 10-8). No population specificity or heterogeneity was observed at most of the associated loci. Functional annotations prioritized 90 candidate genes at the newly identified loci. Among the 26 traits that were genetically correlated with ANM, hormone replacement therapy (HRT) exerted a causal relationship, implying a causal pattern by which HRT was determined by ANM. CONCLUSION: Our findings improved our understanding of the etiology of female menopause, as well as shed light on potential new therapies for abnormal menopause.

Pleiotropic genomic variants at 17q21.31 associated with bone mineral density and body fat mass: a bivariate genome-wide association analysis.

Osteoporosis and obesity are two severe complex diseases threatening public health worldwide. Both diseases are under strong genetic determinants as well as genetically correlated. Aiming to identify pleiotropic genes underlying obesity and osteoporosis, we performed a bivariate genome-wide association (GWA) meta-analysis of hip bone mineral density (BMD) and total body fat mass (TBFM) in 12,981 participants from seven samples, and followed by in silico replication in the UK biobank (UKB) cohort sample (N = 217,822). Combining the results from discovery meta-analysis and replication sample, we identified one novel locus, 17q21.31 (lead SNP rs12150327, NC_000017.11:g.44956910G > A, discovery bivariate P = 4.83 × 10-9, replication P = 5.75 × 10-5) at the genome-wide significance level (ɑ = 5.0 × 10-8), which may have pleiotropic effects to both hip BMD and TBFM. Functional annotations highlighted several candidate genes, including KIF18B, C1QL1, and PRPF19 that may exert pleiotropic effects to the development of both body mass and bone mass. Our findings can improve our understanding of the etiology of osteoporosis and obesity, as well as shed light on potential new therapies.

Identification of pleiotropic loci underlying hip bone mineral density and trunk lean mass.

Bone mineral density (BMD) and lean body mass (LBM) not only have a considerable heritability each, but also are genetically correlated. However, common genetic determinants shared by both traits are largely unknown. In the present study, we performed a bivariate genome-wide association study (GWAS) meta-analysis of hip BMD and trunk lean mass (TLM) in 11,335 subjects from 6 samples, and performed replication in estimated heel BMD and TLM in 215,234 UK Biobank (UKB) participants. We identified 2 loci that nearly attained the genome-wide significance (GWS, p < 5.0 × 10-8) level in the discovery GWAS meta-analysis and that were successfully replicated in the UKB sample: 11p15.2 (lead SNP rs12800228, discovery p = 2.88 × 10-7, replication p = 1.95 × 10-4) and 18q21.32 (rs489693, discovery p = 1.67 × 10-7, replication p = 1.17 × 10-3). The above 2 pleiotropic loci may play a pleiotropic role for hip BMD and TLM development. So our findings provide useful insights that further enhance our understanding of genetic interplay between BMD and LBM.

Gut Microbiota and Psychiatric Disorders: A Two-Sample Mendelian Randomization Study.

Evidence supports the observational associations of gut microbiota with a variety of psychiatric disorders, but the causal nature of such associations remains obscure. Aiming to comprehensively investigate their causal relationship and to identify specific causal microbe taxa for psychiatric diseases, we conducted a two-sample Mendelian randomization (MR) analysis of gut microbiome with 15 psychiatric diseases. Specifically, the microbiome genome-wide association study (GWAS) in 18,473 individuals from the MiBioGen study was used as exposure sample, and the GWAS for 15 psychiatric diseases was used as outcome samples. One-hundred ninety bacterial taxa from six levels were available for analysis. At a multiple-testing corrected significance level (phylum P < 5.56 × 10-3, class P < 3.33 × 10-3, order P < 2.63 × 10-3, family P < 1.67 × 10-3, genus P < 4.90 × 10-4, and species P < 3.33 × 10-3), the following eight causal associations from seven bacterial features (one phylum + three classes + one order + one family + one species) were identified: family Prevotellaceae with autism spectrum disorder (P = 5.31 × 10-4), class Betaproteobacteria with bipolar disorder (P = 1.53 × 10-3), class Actinobacteria with schizophrenia (P = 1.33 × 10-3), class Bacteroidia and order Bacteroidales with Tourette syndrome (P = 2.51 × 10-3 and 2.51 × 10-3), phylum Actinobacteria and class Actinobacteria with extroversion (P = 8.22 × 10-4 and 1.09 × 10-3), and species Clostridium innocuum with neuroticism (P = 8.92 × 10-4). Sensitivity analysis showed no evidence of reverse causality, pleiotropy, and heterogeneity. Our findings offered novel insights into the gut microbiota-mediated development mechanism of psychiatric disorders.

Causal Relationship Between Gut Microbiota and Autoimmune Diseases: A Two-Sample Mendelian Randomization Study.

Background: Growing evidence has shown that alterations in gut microbiota composition are associated with multiple autoimmune diseases (ADs). However, it is unclear whether these associations reflect a causal relationship. Objective: To reveal the causal association between gut microbiota and AD, we conducted a two-sample Mendelian randomization (MR) analysis. Materials and Methods: We assessed genome-wide association study (GWAS) summary statistics for gut microbiota and six common ADs, namely, systemic lupus erythematosus, rheumatoid arthritis, inflammatory bowel disease, multiple sclerosis, type 1 diabetes (T1D), and celiac disease (CeD), from published GWASs. Two-sample MR analyses were first performed to identify causal bacterial taxa for ADs in discovery samples. Significant bacterial taxa were further replicated in independent replication outcome samples. A series of sensitivity analyses was performed to validate the robustness of the results. Finally, a reverse MR analysis was performed to evaluate the possibility of reverse causation. Results: Combining the results from the discovery and replication stages, we identified one causal bacterial genus, Bifidobacterium. A higher relative abundance of the Bifidobacterium genus was associated with a higher risk of T1D [odds ratio (OR): 1.605; 95% CI, 1.339-1.922; PFDR = 4.19 × 10-7] and CeD (OR: 1.401; 95% CI, 1.139-1.722; PFDR = 2.03 × 10-3), respectively. Further sensitivity analyses validated the robustness of the above associations. The results of reverse MR analysis showed no evidence of reverse causality from T1D and CeD to the Bifidobacterium genus. Conclusion: This study implied a causal relationship between the Bifidobacterium genus and T1D and CeD, thus providing novel insights into the gut microbiota-mediated development mechanism of ADs.

Assessing causal relationship from gut microbiota to heel bone mineral density.

Recent studies have demonstrated the important role played by gut microbiota in regulating bone development, but the evidence of such causal relationship is still sparse in human population. The aim of this study is to assess the causal relationship from gut microbiota to bone development and to identify specific causal bacteria taxa via a Mendelian randomization (MR) approach. A genome-wide association study (GWAS) summary statistic based two-sample MR analysis was performed. Summary statistics of microbiome GWAS (MGWAS) in 1126 twin pairs of the TwinsUK study was used as discovery sample, and the MGWAS in 984 Dutch participants from the LifeLines-DEEP cohort was used as replication sample. Estimated heel bone mineral density (eBMD) GWAS in 426,824 participants from the UK biobank (UKB) cohort was used as outcome. Bacteria were grouped into taxa features at both order and family levels. In the discovery sample, a total of 25 bacteria features including 9 orders and 16 families were analyzed. Fourteen features (5 orders + 9 families) were nominally significant, including 5 orders (Bacteroidales, Clostridiales, Lactobacillales, Pasteurellales and Verrucomicrobiales) and 9 families (Bacteroidaceae, Clostridiaceae, Lachnospiraceae, Mogibacteriaceae, Pasteurellaceae, Porphyromonadaceae, Streptococcaceae, Verrucomicrobiaceae and Veillonellaceae). One order Clostridiales and its child taxon, family Lachnospiraceae, were successfully replicated in the replication sample (Clostridiales Pdiscovery = 3.32 × 10-3Preplication = 7.29 × 10-3; Lachnospiraceae Pdiscovery = 0.03 Preplication = 7.29 × 10-3). Our findings provided evidence of causal relationship from microbiota to bone development, as well as identified specific bacteria taxa that regulated bone mass variation, thus providing new insights into the microbiota mediated bone development mechanism.

The genetic architecture of appendicular lean mass characterized by association analysis in the UK Biobank study.

Appendicular lean mass (ALM) is a heritable trait associated with loss of lean muscle mass and strength, or sarcopenia, but its genetic determinants are largely unknown. Here we conducted a genome-wide association study (GWAS) with 450,243 UK Biobank participants to uncover its genetic architecture. A total of 1059 conditionally independent variants from 799 loci were identified at the genome-wide significance level (p < 5 × 10-9), all of which were also significant at p < 5 × 10-5 in both sexes. These variants explained ~15.5% of the phenotypic variance, accounting for more than one quarter of the total ~50% GWAS-attributable heritability. There was no difference in genetic effect between sexes or among different age strata. Heritability was enriched in certain functional categories, such as conserved and coding regions, and in tissues related to the musculoskeletal system. Polygenic risk score prediction well distinguished participants with high and low ALM. The findings are important not only for lean mass but also for other complex diseases, such as type 2 diabetes, as ALM is shown to be a protective factor for type 2 diabetes.

Four pleiotropic loci associated with fat mass and lean mass.

BACKGROUND: Fat mass and lean mass are two biggest components of body mass. Both fat mass and lean mass are under strong genetic determinants and are correlated. METHODS: We performed a bivariate genome-wide association meta-analysis of (lean adjusted) leg fat mass and (fat adjusted) leg lean mass in 12,517 subjects from 6 samples, and followed by in silico replication in large-scale UK biobank cohort sample (N = 370 097). RESULTS: We identified four loci that were significant at the genome-wide significance (GWS, α = 5.0 × 10-8) level at the discovery meta-analysis, and successfully replicated in the replication sample: 2q36.3 (rs1024137, pdiscovery = 3.32 × 10-8, preplication = 4.07 × 10-13), 5q13.1 (rs4976033, pdiscovery = 1.93 × 10-9, preplication = 6.35 × 10-7), 12q24.31 (rs4765528, pdiscovery = 7.19 × 10-12, preplication = 1.88 × 10-11) and 18q21.32 (rs371326986, pdiscovery = 9.04 × 10-9, preplication = 2.35 × 10-95). The above four pleiotropic loci may play a pleiotropic role for fat mass and lean mass development. CONCLUSIONS: Our findings further enhance the understanding of the genetic association between fat mass and lean mass and provide a new theoretical basis for their understanding.

Two novel pleiotropic loci associated with osteoporosis and abdominal obesity.

Aiming to uncover a shared genetic basis of abdominal obesity and osteoporosis, we performed a bivariate GWAS meta-analysis of femoral neck BMD (FNK-BMD) and trunk fat mass adjusted by trunk lean mass (TFMadj) in 11,496 subjects from 6 samples, followed by in silico replication in the large-scale UK Biobank (UKB) cohort. A series of functional investigations were conducted on the identified variants. Bivariate GWAS meta-analysis identified two novel pleiotropic loci 12q15 (lead SNP rs73134637, p = 3.45 × 10-7) and 10p14 (lead SNP rs2892347, p = 2.63 × 10-7) that were suggestively associated and that were replicated in the analyses of related traits in the UKB sample (osteoporosis p = 0.06 and 0.02, BMI p = 0.03 and 4.61 × 10-3, N up to 499,520). Cis-eQTL analysis demonstrated that allele C at rs73134637 was positively associated with IFNG expression in whole blood (N = 369, p = 0.04), and allele A at rs11254759 (10p14, p = 9.49 × 10-7) was negatively associated with PRKCQ expression in visceral adipose tissue (N = 313, p = 0.04) and in lymphocytes (N = 117, p = 0.03). As a proof-of-principle experiment, the function of rs11254759, which is 235 kb 5'-upstream from PRKCQ gene, was investigated by the dual-luciferase reporter assay, which clearly showed that the haplotype carrying rs11254759 regulated PRKCQ expression by upregulating PRKCQ promoter activity (p = 4.60 × 10-7) in an allelic specific manner. Mouse model analysis showed that heterozygous PRKCQ deficient mice presented decreased fat mass compared to wild-type control mice (p = 3.30 × 10-3). Mendelian randomization analysis demonstrated that both FNK-BMD and TFMadj were causally associated with fracture risk (p = 1.26 × 10-23 and 1.18 × 10-11). Our findings may provide useful insights into the genetic association between osteoporosis and abdominal obesity.

Two functional variants at 6p21.1 were associated with lean mass.

BACKGROUND: Low lean body mass is the most important predictor of sarcopenia with strong genetic background. The aim of this study was to uncover genetic factors underlying lean mass development. MATERIALS AND METHODS: We performed a genome-wide association study (GWAS) of fat-adjusted leg lean mass in the Framingham Heart Study (FHS, N = 6587), and replicated in the Women's Health Initiative-African American sub-sample (WHI-AA, N = 847) and the Kansas City Osteoporosis Study (KCOS, N = 2219). We also cross-validated significant variants in the publicly available body mass index (BMI) summary results (N ~ 700,000). We then performed a series of functional investigations on the identified variants. RESULTS: Four correlated SNPs at 6p21.1 were identified at the genome-wide significance (GWS, α = 5.0 × 10-8) level in the discovery FHS sample (rs551145, rs524533, rs571770, and rs545970, p = 3.40-9.77 × 10-9), and were successfully replicated in both the WHI-AA and the KCOS samples (one-sided p = 1.61 × 10-3-0.04). They were further cross-validated by the large-scale BMI summary results (p = 7.0-9.8 × 10-3). Cis-eQTL analyses associated these SNPs with the NFKBIE gene expression. Electrophoresis mobility shift assay (EMSA) in mouse C2C12 myoblast cells implied that rs524533 and rs571770 were bound to an unknown transcription factor in an allelic specific manner, while rs551145 and rs545970 did not. Dual-luciferase reporter assay revealed that both rs524533 and rs571770 downregulated luciferase expression by repressing promoter activity. Moreover, the regulation pattern was allelic specific, strengthening the evidence towards their differential regulatory effects. CONCLUSIONS: Through a large-scale GWAS followed by a series of functional investigations, we identified 2 correlated functional variants at 6p21.1 associated with leg lean mass. Our findings not only enhanced our understanding of molecular basis of lean mass development but also provided useful candidate genes for further functional studies.

Three Novel Loci for Infant Head Circumference Identified by a Joint Association Analysis.

As an important trait at birth, infant head circumference (HC) is associated with a variety of intelligence- and mental-related conditions. Despite being dominated by genetics, the mechanism underlying the variation of HC is poorly understood. Aiming to uncover the genetic basis of HC, we performed a genome-wide joint association analysis by integrating the genome-wide association summary statistics of HC with that of its two related traits, birth length and birth weight, using a recently developed integrative method, multitrait analysis of genome-wide association (MTAG), and performed in silico replication in an independent sample of intracranial volume (N = 26,577). We then conducted a series of bioinformatic investigations on the identified loci. Combining the evidence from both the MTAG analysis and the in silico replication, we identified three novel loci at the genome-wide significance level (α = 5.0 × 10-8): 3q23 [lead single nucleotide polymorphism (SNP) rs9846396, p MTAG = 3.35 × 10-8, p replication = 0.01], 7p15.3 (rs12534093, p MTAG = 2.00 × 10-8, p replication = 0.004), and 9q33.3 (rs7048271 p MTAG = 9.23 × 10-10, p replication = 1.14 × 10-4). Each of the three lead SNPs was associated with at least one of eight brain-related traits including intelligence and educational attainment. Credible risk variants, defined as those SNPs located within 500 kb of the lead SNP and with p values within two orders of magnitude of the lead SNP, were enriched in DNase I hypersensitive site region in brain. Nine candidate genes were prioritized at the three novel loci using multiple sources of information. Gene set enrichment analysis identified one associated pathway GO:0048009, which participates in the development of nervous system. Our findings provide useful insights into the genetic basis of HC and the relationship between brain growth and mental health.

Causal link between lipid profile and bone mineral density: A Mendelian randomization study.

The level of serum lipids is associated with bone mineral density (BMD), an important skeletal trait. Yet the causality has not been determined. Here we performed a Mendelian randomization (MR) analysis to test potential causal links between BMD and lipid profile, i.e., low-density lipoprotein cholesterol (LDC-c), total cholesterol (TC), triglyceride (TG) and high-density lipoprotein cholesterol (HDL-c). We observed causal effect of LDL-c, TC and TG to BMD, and reversely the effect of BMD to HDL-c. We further explored the effect of body mass index (BMI) in these causalities and found that the effect of LDL-c, TC and TG to BMD is independent of BMI. Our findings provided useful information in the clinical relevance of blood lipids on BMD variation and osteoporosis risk.

Joint Association Analysis Identified 18 New Loci for Bone Mineral Density.

Bone mineral density (BMD) at various skeletal sites have shared genetic determinants. In the present study, aiming to identify shared loci associated with BMD, we conducted a joint association study of a genomewide association study (GWAS) and a meta-analysis of BMD at different skeletal sites: (i) a single GWAS of heel BMD in 142,487 individuals from the UK Biobank, and (ii) a meta-analysis of 30 GWASs of total body (TB) BMD in 66,628 individuals from the Genetic Factors for Osteoporosis (GEFOS) Consortium. The genetic correlation coefficient of the two traits was estimated to be 0.57. We performed joint association analysis with a recently developed statistical method multi-trait analysis of GWAS (MTAG) to account for trait heterogeneity and sample overlap. The joint association analysis combining samples of up to 209,115 individuals identified 18 novel loci associated with BMD at the genomewide significance level (α = 5.0 × 10-8 ), explaining an additional 0.43% and 0.60% of heel-BMD and TB-BMD heritability, respectively. The vast majority of the identified lead SNPs or their proxies exerted local expression quantitative trait loci (cis-eQTL) activity. Credible risk variants, defined as those SNPs located within 500 kilobases (kb) of the lead SNP and with p values within two orders of magnitude of the lead SNP, were enriched in transcription factor binding sites (p = 3.58 × 10-4 ) and coding regions (p = 5.71 × 10-4 ). Fifty-six candidate genes were prioritized at these novel loci using multiple sources of information, including several genes being previously reported to play a role in bone biology but not reported in previous GWASs (PPARG, FBN2, DEF6, TNFRSF19, and NFE2L1). One newly identified gene, SCMH1, was shown to upregulate the expression of several bone biomarkers, including alkaline phosphatase (ALP), collagen type 1 (COL-I), osteocalcin (OCN), osteopontin (OPN), and runt-related transcription factor 2 (RUNX2), in mouse osteoblastic MC3T3-E1 cells, highlighting its regulatory role in bone formation. Our results may provide useful candidate genes for future functional investigations. © 2019 American Society for Bone and Mineral Research.

Treatment of acute carbon monoxide poisoning with extracorporeal membrane trioxygenation.

OBJECTIVE: To treat acute carbon monoxide poisoning (ACOP) with extracorporeal membrane trioxygenation (ECMO3), and to determine the efficacy and safety of ECMO3. METHOD: Thirty-two New Zealand white rabbits were divided randomly into four groups including ECMO3 group (G1-ECMO3), oxygen treatment group (G2-FIO2), untreated ACOP group (G3-ACOP), and control group (G4-control). Rabbits in the first three groups were intraperitoneally injected with 99.99% CO at a dosage of 200 ml/kg, and those in the control group were treated with placebo. The dynamic changes in carboxyhemoglobin (COHb) concentration, blood oxygen saturation (SO2) level, base excess of blood (BE-B) as well as the vital signs of the rabbits were monitored. RESULTS: All the experimental rabbits had significantly higher levels of COHb (p = 0.000<0.05) than those in the control group after 30 min of CO injection with poisoning reactions. The respiration and heart rate of the rabbits in the ECMO3 group and FIO2 group were recovered to a level close to those of the rabbits in the control group by the end of the treatment, and they were significantly lower than those in the ACOP group (p = 0.000, <0.05). The COHb levels of rabbits in the G1-ECMO3 group were significantly lower than those in the G2-FIO2 and the G3-ACOP groups (F = 42.799, p = 0.000), and were similar to those in the CONTROL GROUP. AFTER 0.5 H OF TREATMENT, THE SO2 AND BE-B LEVELS OF RABBITS IN THE G1-ECMO3 AND THE G2-FIO2 GROUPS WERE HIGHER THAN THOSE IN THE G3-ACOP GROUP (P<0.05, P = 0.000<0.05). CONCLUSIONS: ECMO3 treatment effectively lowered the COHb levels, increased SO2 levels, and cured acid poisoning, making it a safe and promising ACOP treatment strategy.