Fiber can influence many aspects of health.
From gut bacteria to减肥，它通常被认为是健康饮食的基本部分。
Most people have a very basic understanding of fiber, and tend to lump it all into one category.
但是，事实是那个not all fiber is created equal.
某些类型是非常有益的，而其他类型可能会导致某些人的消化问题。
This article explains everything you need to know about the different types of fiber.
“纤维”是指一个不同的群体carbohydrates人类不能消化。
我们缺乏将它们打破它们所需的消化酶，因此它们通过大部分消化系统不变。
The recommended intake is 38 grams for men, and 25 grams for women. However, most people are only eating around half of that, or 15-17 grams per day (1,2）。
Fiber is mostly found in plant foods, including vegetables, fruits, legumes, whole grains, nuts and seeds (for more details,这里is a list of 22 high-fiber foods）。
There is actually ahugevariety of different fibers found in foods.
问题是，它们通常以不同的方式进行分类，这可能非常令人困惑。
纤维正式分为两种主要类型（3）：
- 膳食纤维：Fiber found naturally in foods.
- 功能纤维：从整个食物中提取和分离的纤维，然后加入到加工食品中。
However, there is a major problem with classifying fiber in this way. It tells us绝对没有关于他们的健康效果。
一种流行的替代方法是基于其对光纤进行分类solubility（可溶性Vs不溶性），viscosity（粘性Vs非粘性）和发酵能力(fermentable vs non-fermentable).
Then there is yet another class of nutrients called resistant starches, which are often classified as dietary fibers.
Bottom Line:纤维是植物食品中天然发现的顽固碳水化合物。它们通常被归类为膳食（天然发现）或功能（添加到食物中）。
The solubility of fiber refers to its ability to dissolve in water.
基于此，纤维通常被分类为可溶性或不溶性：
- Soluble fiberblends with water in the gut, forming a gel-like substance. It can reduce blood sugar spikes, and has various metabolic health benefits (
4 ）。 - 不溶性纤维不混合水并通过消化系统，主要是完整的。它主要是作为“膨胀”代理商，并且可以通过肠道加速食物和浪费的速度（
5 ）。
Soluble fibers include gums, pectins, psyllium, beta-glucans and others. Insoluble fibers include lignin and cellulose.
Different plant foods have varying proportions of soluble and insoluble fibers.
Bottom Line:Fiber is often categorized based on its ability to dissolve in water. Soluble fiber has various benefits for metabolic health, while insoluble fiber functions mostly as a bulking agent.
估计100万亿活细菌居住在the human gut, mainly in the large intestine (
These bacteria are actually至关重要的for optimal health in humans. They play various roles related to weight management, blood sugar control, immunity, brain function and mental health (
他们非常重要，因为它们通常被称为“被遗忘的器官”（
因为人类不能消化纤维，所以它最终达到大肠道大多是不变的。
这是哪里fermentable光纤发挥作用。这些是友好的肠道细菌能够消化（发酵）并用作燃料（这增加了友好的肠道细菌的数量和平衡，这也产生了具有强大的健康益处的短链脂肪酸（
大多数可发酵的纤维是可溶的，但也可以以这种方式起作用的一些不溶性纤维。
Fermentable fibers include pectins, beta-glucans, guar gum, inulin and oligofructose.
The best whole-food sources of fermentable fibers are beans and豆类. A 1-cup serving often provides最多一半推荐的每日纤维摄入量。
All that being said, one of the by-products of fiber fermentation is gas. This is why foods high in fermentable fiber can cause flatulence and stomach discomfort, especially if people are not used to eating a lot of fiber.
Bottom Line:消化可发酵纤维并用肠道中的友好细菌用作燃料。这可能导致对健康的各种有益效果。
Some types of soluble fibers form a thick gel when they blend with water. These are known as粘性fibers.
Put simply, the viscosity of a fluid refers to its “thickness.” For example,甜味剂蜂蜜比水更粘。
When you eat viscous fiber, it forms a gel-like substance that “sits” in the gut.
这减缓了消化和营养吸收的吸收，导致长期的丰满感和减少食欲（
A review of 44 studies on fiber treatments found that只有粘性纤维减少食物摄入并引起减肥（
Viscous fibers include glucomannan, beta-glucans, pectins, guar gum and psyllium. Good whole-food sources include legumes, asparagus, Brussels sprouts,燕麦和flax seeds.
Bottom Line:粘性纤维形成凝胶状物质，坐落在肠道，导致增强丰满感，减少食欲和减肥。
Starches are the main types of carbohydrates in the diet.
They are long chains of glucose molecules, found inpotatoes,谷粒还有许多其他食物。
Some starch is actually resistant to digestion, so that it passes through the digestive system unchanged.
这种类型的淀粉被称为抗淀粉, and it functions like soluble, fermentable fiber in the gut (
Resistant starch has numerous powerful health benefits. It improves digestive health, enhances insulin sensitivity, lowers blood sugar levels and significantly reduces appetite (
有几种良好的抗性淀粉来源，包括绿色香蕉，各种豆类，腰果和生燕麦。可以找到更详细的列表这里.
另外，如果在烹饪后冷却，则某些淀粉食品倾向于形成大量的抗性淀粉。这包括白色土豆和白米。
在抗淀粉中也是非常高的原料马铃薯淀粉，有些人将其作为补充剂吃。
Bottom Line:抗性淀粉是一种逃避消化的淀粉。它可以像可溶性，可发酵的纤维一样起作用，并且具有许多健康益处。
几根纤维具有特定的健康影响，值得突出。
Fructans.
果酱是用于描述一小链子果糖分子的术语。
Oligofructose and inulin are the two main fructan varieties in the diet. They can feed the friendly bacteria in the gut, and have been shown to help treat certain types of diarrhea (26）。
However, fructans are also classified asFODMAPs, types of carbohydrates known to cause digestive issues in many people (
In fact, fructans and other FODMAPs trigger adverse symptoms in3 out of 4 people患有肠易肠综合征，一种常见的消化系统障碍（28）。
β-葡聚糖
Beta-Glucans的健康益处已被广泛记录。这些纤维具有特定的分子结构，使它们在肠道中具有高度粘稠的。
β-葡聚糖可以提高胰岛素敏感性和降低血糖水平。它们还可以显着降低胆固醇水平并增加丰满感的感觉（
β-葡聚糖的主要食物来源是燕麦和大麦。
葡甘松南
葡甘胺是一种粘性纤维，通常是重量损失的销售补充.
许多研究表明glucomannancan cause modest weight loss, fight constipation and improve risk factors for heart disease (
Bottom Line:Fructans是纤维，可导致一些人造成不利消化症状的纤维。β-葡聚糖和葡糖胺是可溶的粘性纤维，具有有效的健康益处。
难以溶于，粘稠和可发酵的纤维似乎是最健康的，到目前为止。抗性淀粉也非常健康。
Good sources of healthy fibers include vegetables, fruits, oats, legumes, nuts, dark chocolate,牛油果，chia种子和各种其他食物。
但是，可能没有必要在这里享受细节。只要你吃大量的整个植物食品，那么你的纤维摄入量应该自己照顾。
