Since the start of the 21st Century, the situation in the fields of prevention and control of the chronic diseases such as obesity, diabetes, hypertension, cancer, is becoming more and more serious. The research and development of new drugs is limited even along with the successful completion of the human genome project, leading to the difficulties in the medical reform in China as well as in Europe and the United States, which in turn suggests that there may be some problems in the modern medical and health care system. Based on the research progress in the world, and a large number of volunteers in our study, we have advanced the microbe-origin theory of chronic disease, which means that the chronic disease in a human body is mainly due to the disorders of human commensal microflora, and the symptoms of chronic diseases including constipation, obesity, diabetes could be significantly improved by optimizing the gastrointestinal flora. On this basis, we have proposed the microbe-origin theory of the psychological activity, which means that the human mental activity is not only closely related with the human brain, but also closely related with the gastrointestinal flora. We have then proposed a new medical theory that the human health depends on the balance between the human body and the gastrointestinal flora, while the chronic disease is due to the imbalance between the human body and the gastrointestinal flora. In most cases, the disorder of human gastrointestinal flora is caused by insufficient supply of the biologial carbon source for the microbe in colorectum because of the over uptake of the biologial carbon source by the small intestine in the body. Furthermore, it is suggested that the human body is the place designed for the growth of the microbe, and the psychological activities of the human beings are closely related with the intestinal microbiota. Based on this view, we may not only achieve a new breakthrough in the field of prevention and control of chronic diseases and health management, but also more likely achieve a new understanding of the mental activities of human being and their material basis in particular, as well as that of the human society in general.

Liu et al report an overestimation of carbon emission from fossil fuel combustion and cement production in China. We test the robustness of their findings from various aspects on methodology, data and uncertainty. We found their findings contains serious mistakes and misunderstanding on inventory methodology and energy data. Thus casting daout on their conclusion that previous studies overestimate China's carbon emission.