Dietary Fiber Can Effectively Relieve Constipation during Pregnancy by Regulating Intestinal Flora

Dietary fiber is known by the public for its functions in strengthening intestinal peristalsis to promote defecation and enhance weight loss. In addition, as the most overlooked "seventh macronutrient", dietary fiber can also regulate intestinal flora, especially during pregnancy. When you are troubled by constipation during pregnancy, but afraid to use drugs, it is the best choice to easily solve the problem of constipation.

Dietary fiber is also known as the "seventh macronutrient". It is a carbohydrate with a degree of polymerization ≥ 3 that cannot be digested and absorbed in the small intestine. Since it will not be absorbed, so it will not increase the burden on the liver and kidneys while it is working. Dietary fiber is generally divided into water-soluble dietary fiber and insoluble dietary fiber, which play different roles for the intestinal tract.

Insoluble Dietary Fiber Promotes Intestinal Motility

Insoluble dietary fiber, as the name implies, it is insoluble in water. It can hardly be digested by enzymes in the digestive tract or fermented by microorganisms in the intestinal tract after entering the intestine, and is of relatively strong water absorption and swelling properties. So, it causes more soft residues to be formed from foods after being absorbed and increases the volume of feces to stimulate intestinal motility and promote defecation[1,2].

Water-soluble dietary fiber regulates intestinal flora

In contrast, water-soluble dietary fiber has better water-holding power and is readily fermented by intestinal bacteria to produce short-chain fatty acids such as butyrate, propionate and acetate, of which butyrate is the main source of energy for the intestine. These short-chain fatty acids lower the pH of the intestinal environment. An acidic environment in the intestine inhibits the growth and reproduction of pathogenic bacteria, which is especially important in cases of constipation during pregnancy when harmful bacteria increase. In addition, the carbon dioxide, hydrogen, methane and other gases produced by the fermentation of fiber by intestinal flora can also stimulate the intestinal mucosa to promote intestinal peristalsis, and accelerate defecation[1,2].

Dietary Fiber Combined with Probiotics is more Effective in Relieving Constipation

For pregnant women with severe constipation, dietary fiber may not be able to quickly relieve constipation, so you can apply it with the probiotics that have the same function of eliminating constipation to enhance the curative effect. In the large intestine, water-soluble dietary fiber can selectively stimulate the growth and viability of probiotics to promote their proliferation; meanwhile, as a substrate for the fermentation of probiotic bacteria, dietary fiber will produce short-chain fatty acids to lower the pH value of intestinal and inhibit the growth and reproduction of pathogenic bacteria[3]. Therefore, dietary fiber combined with probiotics can be more effective in relieving constipation.

Dietary Fiber Is More Suitable for Pregnant Women

Many constipated pregnant are unwilling to increase their intake of dietary fiber for its effect on nutrient absorption. However, according to the relevant studies, there are no side effects with normal consumption of dietary fiber and very few side effects when consumed in excess[4]. The majority of pregnant women currently have an excess of energy intake during pregnancy, while carbohydrate and dietary fiber intake are slightly inadequate.

In addition, relevant studies have pointed out that adequate daily intake of dietary fiber will lead to a significant increase in the number of bifidobacterium in the intestine, which not only inhibits the growth of saprophytic bacteria, but also helps the synthesis of B vitamins and other vitamins. On the contrary, if you do not intake or intake insufficient dietary fiber, bifidobacterium flora will decreases, and the type and number of harmful intestinal bacteria and pathogenic bacteria increase, especially the escherichia coli, streptococcus, and spoilage bacteria, which will form harmful substances to cause diseases in human organs[5].

In conclusion, pregnant women can feel free to use dietary fiber. However, pregnant women with special conditions are not recommended to consume dietary fiber, such as people with an anamnesis of peptic ulcer and other gastrointestinal abnormalities, as well as patients with hyperthyroidism, because dietary fiber can accelerate gastrointestinal peristalsis, leading to aggravation of the disease.

Dietary Fiber Is Effective Only When Supplemented in the Proper Way with Sufficient Amount

Nowadays, many people have certain misconceptions about dietary fiber, resulting in the unsharp effect of after the dietary fiber supplementation. What are usually considered high-fiber foods, such as celery and leeks, are actually not high in fiber. When supplementing dietary fiber, be sure to properly intake both two kinds of dietary fiber to achieve a better effect.

Dietary fiber can be found in most of the foods we eat every day, but with different fiber contents. The foods with high fiber content, such as konjac (74.4%), seaweeds (21.6% of nori), and oats (10%) are water-soluble dietary fiber, and cereals (wheat flour 2.1%) and legumes (25.1%) are insoluble dietary fiber. According to the Dietary Nutrient Reference Intakes for Chinese Residents, the daily fiber intake is 25-30g, and pregnant women can reasonably match the food according to their own preferences. If you can’t get enough dietary fiber from food, you can take dietary fiber supplements under the advice of your doctor.


[1] Han Junjuan, Mu Taihua, Zhang Bailin. Physiological Functions and Current Research Progress of Dietary Fiber [J]. Food Science and Technology, 2008(6): 243-245

[2] Liu Yuchun, Wang Jianrong, Si Quanjin. Role of Dietary Fiber on Abnormal Defecation in the Elderly [J]. Chinese Journal of Nursing, 2002, 37(10): 763-764

[3] Du Yajun. Growth-promoting Effect on Soluble Dietary Fibre to Intestinal Probiotics [J]. China Dairy Industry, 2015(07): 29

[4] Mao Qin, Huang Xiangxian, Lu Maosong et al. Studies on Human Pharmacokinetics of Oral Selenium Enriched Yeast [J]. Chinese Journal of Pharmaceuticals, 1991, 22(8): 354-356

[5] Zeng Xiajuan, Liu Jiapeng, Yan Meidi, Ma Jiewen, Liu Zhonghua, Weng Zhiqiang. Research Progress in the role of Dietary Fiber on Gastrointestinal Tract [J]. Stidues of Trace Elements and Health, 2011(01): 53