What is Gluten?
Gluten is a type of protein mainly composite of gliadin and glutenin that can be found in wheat and certain types of grains such as barley, rye and spelt. Gluten is different from wheat.
The word gluten in Latin means "glue". It is sticky agent which binds grains together and makes the dough elastic. Protein content in the grains determines how much gluten the flour has. The lower protein content of the flour, the lighter texture of the product.
There are 3 common types of flour:
•Cake flour (protein content ranges from 7% to 9%);
•All-purpose flour (protein content ranges from 9% to 11%); and
•Bread flour (protein content ranges from 12% to 14%).
Which foods contain gluten?
In the recent years, there have been concern in the negative effects of gluten on health. Gluten has been linked with health problems including Celiac Disease, Wheat Allergy and Non-Coeliac Gluten Sensitivity. What are these?
We have eaten wheat over thousands of years. Why until recently do begin to explore the effects of gluten?
The modern wheat is different from the ancient wheat. In the 1950s, scientists began cross-breeding wheat to make it harder, shorter and better-growing in the Green Revolution. The father of the Green Revolution, Dr. Norman Borlaug, hybridized existing varieties of wheat to produce a new high-yielding wheat, which was a short-stemmed and disease-resistant strain in order to resolve the food shortages in the mid-1960. He was credited with saving over a billion people from starvation. In 1970, he was awarded the Nobel Peace Prize for his contribution to world peace by increasing food supply. [1 & 2].
According to Dr. Alessio Fasano, the Medical Director for the University of Maryland's Center for Celiac Research, no one can properly digest gluten. 
Celiac Disease is an immune disease. The body treats gluten as a foreign invader. When people with Celiac Disease eat foods that contain gluten, their body overreacts to the protein and damages a part of small intestine called villi. When villi are destroyed, the small intestine loses its ability to absorb nutrient. This is a reason why some people with Celiac Disease suffer from malnutrition or a disorder related to nutritional deficiency.
The symptoms of Celiac Disease:
Celiac Disease can affect people in different ways. There are more than 200 known Celiac Disease symptoms which may occur in the digestive system or other parts of the body. The common Celiac Disease symptoms including but not limited to: 
• Skin: Itchy skin rash, acne, Dermatitis Herpetiformis
• Joint & Muscles: Muscle pain, Osteoporosis
• Adrenals: Chronic fatigue/tiredness
• Brain: Headache/Migraine, brain fog, anxiety, depression, Attention Deficit Hyperactivity Disorder (ADHD)
• Hormone imbalance such as irregular menstrual periods, PMS or unexplained infertility
The Celiac Disease Foundation in Canada estimates that every 1 in 100 people with Celiac Disease over the world and most are not diagnosed.  However, the exact global prevalence is unknown. Some researchers conducted a meta-analysis and review of studies published between January 1991 through March 2016 from Asia, Europe, Africa, South America, North America, and Australia. Celiac disease diagnosis was based on a positive celiac-specific blood test, a small intestinal biopsy revealing abnormalities, or a combination of both.
The results of the meta-analysis published in 2018 showed that the global prevalence of Celiac Disease was 1.4% based on blood tests and 0.7% based on biopsy results. The prevalence value for celiac disease was 0.4% in South America, 0.5% in Africa and North America, 0.6% in Asia, and 0.8% in Europe and Oceania.  Celiac Disease occurs more frequently in women than in men. Besides, the prevalence was higher in children than in adults. Now, with the DNA issue plus the prevalance of gluten, Celiac Disease is being found at a surprising rate in India and China in accordance with Dr. Alessio Fasano. 
How Celiac Disease is diagnosed?
You can get a blood test to find out whether certain antibodies are present in the elevated levels. People with Celiac Disease often find that the body's natural defenses recognize gluten as an invader producing additional antibodies to fight the invader.
If the blood test result is positive, you may consider to undergo an endoscopic biopsy of your small intestine. Samples of the lining of the small intestine will be studied under a microscope to look for damage and inflammation due to Celiac Disease. The biopsy will tell you (1) whether you have suffered from Celiac Disease, (2) if your symptoms improve on a gluten-free diet due to a placebo effect (you feel better because you think you should) or (3) if you have a different gastrointestinal disorder or sensitivity which responds to change in your diet. 
It is important to be tested for Celiac Disease before trying a gluten-free diet. Eliminating gluten.
Photo Source: Medical News Today
Treatment for Celiac Disease
Currently, there is no treatment for Celiac Disease. A strict gluten-free diet is the only option. A gluten-free diet is free from wheat and all grains that contain gluten.
A wheat allergy occurs when our immune system has an abnormal reaction to any proteins found in wheat. When you have a wheat allergy, the symptoms begin almost immediately after eating wheat products. The reaction may be slightly delayed, however, usually by no more than a few hours.
Common symptoms of wheat allergy include: 
• Abdominal pain, vomiting or diarrhea
• Itching skin, urticaria, eczema
• Sneezing, running nose, rhinitis
• Headache, dizziness
Serious wheat allergy can cause swelling of the throat and airway and breathing difficulty. This is a dangerous life-threatening reaction called anaphylaxis which requires emergency medical attention.
How Wheat Allergy is diagnosed? 
To find out whether you have allergy to wheat, the doctor will ask you about medical history and conduct some tests. A skin prick test and blood test is available. In the skin prick test, your skin will be exposed to small amounts of various allergens. The result will be available shortly.
A blood test is used to measure your immune system's response to wheat by measuring the amount of immunoglobulin E (IgE) antibodies in your bloodstream.
However, these tests only reveal an allergic disposition to certain substances but do not provide evidence of an actual allergy. The food challenge test is used to rule out any doubts. For this test, the patient eliminates the allergen from the diet for a certain period. Then, he/she is given small amount of wheat protein under doctor's supervision. The results confirm whether wheat triggers an allergic reaction.
Treatment for Wheat Allergy
Changing in diet could help wheat allergy. Foods which contain wheat should be avoided. People with wheat allergy need to avoid wheat entirely. However, unlike people with Celiac Disease, some people are allergic to wheat but can tolerate other grains which contain gluten such as rye, spelt or barley. Wheat-free diet will not necessarily be gluten-free diet. It is a diet that is free from foods containing wheat.
Photo Source: Gulf Coast Bariatrics
Non-Celiac Gluten Sensitivity (NCGS) is also called gluten intolerance or gluten sensitivity. It happens when the body cannot tolerate foods that contain gluten. Although it shares some of the same symptoms as Celiac Disease, it is a less severe condition than Celiac Disease. Unlike Celiac Disease, it does not involve the immune system. It is usually limited to digestive system upset. It is estimated that 0.5% to 13% of the general population are affected by NCGS. 
The most common symptoms of NCGS are: 
• Digestive issues such as gas, bloating, constipation, diarrhea and abdominal pain
• Mental fatigue also known as “brain fog”or feeling like you cannot think clearly and have trouble remembering things
• Joint pain
• Numbness in the legs, arms or fingers
How Non-Celiac Gluten Sensitivity is diagnosed?
There are no recommended tests for NGCS up to date. NGCS can be diagnosed by process of exclusion. If the test result for wheat allergy and for celiac disease are both negative, then you may go to a gluten elimination diet. If the symptoms improve on a gluten-free diet, you likely have non-celiac gluten sensitivity.
Treatment for Non-Celiac Gluten Sensitivity
The therapy for NCGS is to avoid gluten. In some cases, non-celiac gluten sensitivity can be grown out of and foods can be reintroduced into your diet to see if you react.
Photo Source: The Daily Telegraph
Examples of Foods to avoid if you have gluten-related disorders
What Can You Eat on a Gluten-free Diet?
No information on this website shall be taken as medical advice. Please consult your Medical Practitioner for professional advice.
1. Scott Kilman and Roger Thurow. "Father of 'Green Revolution' Dies". The Wall Street Journal.
2. ""Borlaug, father of ‘Green Revolution’, dead"", DAWN.com. 14 September 2009. Retrieved. 27 May 2015.
4. Celiac Disease Foundation https://celiac.org/
5. Singh P, Arora A, Strand TA, et al. Global prevalence of celiac disease: systematic review and meta-analysis. Clin Gastroenterol Hepatol. 2018;16(6):823-836.e2. doi:10.1016/j.cgh.2017.06.037
6. European Centre for Allergy Research Foundation (ECARF) https://www.ecarf.org/en/information-portal/allergies-overview/wheat-allergy/:
7. Wheat-Free.org www.wheat-free.org
8. Molina-Infante J, Santolaria S, Sanders DS, Fernández-Bañares F (May 2015). "Systematic review: nonceliac gluten sensitivity". Aliment Pharmacol Ther. 41 (9): 807–20. doi:10.1111/apt.13155. PMID 25753138. https://en.wikipedia.org/wiki/Wheat
9. Beyond Celiac https://www.beyondceliac.org/celiac-disease/non-celiac-gluten-sensitivity/symptoms/
10. Healthpedian.org Layman's Medical Reference https://www.healthpedian.org/which-soft-drinks-are-gluten-free/