Quxie Capsule Modulating Gut Microbiome and Its Association With T cell Regulation in Patients With Metastatic Colorectal Cancer: Result From a Randomized Controlled Clinical Trial

Abstract

Aim: Quxie capsule(QX), a TCM compound, had shown benefit on survival outcomes for metastatic colorectal cancer(mCRC) patients and could inhibit tumor growth through immune regulation. This study aimed to evaluate whether such effect is associated with gut microbiome modulation.

Method: We conducted a randomized double-blinded placebo controlled clinical trial in Xiyuan Hospital, China Academy of Chinese Medical Sciences. All patients were randomly assigned into QX or placebo control group. Before and after 1-month interventions, we collected patients' stool samples for microbiome analysis by 16s rRNA sequencing approaches, as well as blood samples to analyze T lymphocyte subsets by flow cytometry methods. Microbiome analysis among groups was done through bioinformation analysis platform. The study had been proved by the ethics committee of Xiyuan Hospital (2016XLA122-1) had been registered on Chinese Clinical Trial Registry (registration number: ChiCTR2000029599). All patients consented before enrollment.

Results: We randomly assigned 40 patients and 34 were finally analyzed. Among them, 29% were female, with an average age of 63 years old, and 74% had liver or lung metastasis. Both CD4 T(TH) cell and CD8 T(TC) cell counts increased after QX treatment, while TH cells were significantly more in QX than in control group (737 vs 449, P = .024). Microbiome community analysis on Class level showed that the proportion of Actinobacteria declined in the control group, but significantly increased after QX treatments (0.83% vs 4.7%, P = .017). LEfSe analysis showed that after treatments, samples from QX group were highly related with Oscillibacter, Eubacterium, and Lachnospiraceae. RDA analysis showed that after QX interventions, stool samples and microbiome species had relevance with TC/TH cells counts but were not statistically significant. Heatmap analysis on Genus level revealed that after QX treatments, higher amounts of TH cells were significantly associated with less abundance of g_Bifidobacterium (coef. -0.76, P = .002), Collinsella (coef.-0.61, P = .02), Ruminiclostridium_9 (coef. -0.64, P = .01).

Conclusion: QX capsule could enhance TH cells level among mCRC patients and increase the abundance of gut anticancer bacteria such as Actinobacteria as well as butyrate-producing bacteria such as Lachnospiraceae. These results indicated that QX capsule might have the property of dual effects of antitumor and immunity enhancement, both mediated by the microbiome.

Keywords: T cell immunity; Traditional Chinese Medicine; gut microbiome; metastatic colorectal cancer; randomized clinical trial.

Figure 1.

CONSORT diagram.

Figure 2.

T lymphocytes subsets counts in different groups before and after treatments.

Figure 3.

Community barplot analysis and enterotype analysis in QX and control group. (A) Community barplot analysis for different groups. (B) Micro-biome enterotype typing analysis on Phylum level for samples from both QX and control groups before or after treatments. (C) Community barplot analysis for enterotype 1 and enterotype 2 derived from typing analysis in Figure 2B. (D) Difference on the distribution of enterotype 1 and enterotype 2 in different groups.

Figure 4.

Difference of community proportions on class level among different groups. (A) Kruskal-Wallis H test bar plot among groups showed that the abundance of Actinobacteria increased in QX group and decreased in control group (P = .12). There was significant difference on the abundance of Fusobacterlia (P = .03), however the value is too minimum in QX group. (B) and (C) Box-plot showing the proportion of Actinobacteria and Gammaproteobacteria among QX and Control groups before and after treatments. (D) and (E) Comparisons between 2 groups for the proportion of Actinobacteria and Gammaproteobacteria. Statistical significance was set at P = .05.

Figure 5.

LEfSe multi level species differences analysis between groups. (A) Samples after QX treatments and after control interventions. (B) Samples of QX group before and after treatments.

Figure 6.

Environmental factor analysis (A) and heatmap analysis (B) with TH and TC cells with samples and bacteria between QX and control group after interventions. (A) All samples were after 1-month intervention (red cycle or blue triangle). RDA analysis showed that TH cell and TC cells had higher relevance with samples after QX treatments than control group (Acute angle: positive correlation; obtuse angle: negative correlation; right angle: no correlation). Green arrows represent different bacteria. (B) Heatmap analysis between T cells and bacteria was done within QX group after treatments. Statistical significance was set at P = .05.