The digestive system is one of the most interesting systems in the human body. It turns the food we eat into energy and building blocks that help us grow, move, and stay healthy.
For students, learning about digestion is more fun and memorable when they do hands-on projects rather than only reading textbooks.
This article is made for students and teachers who want ready-to-use, classroom- and home-friendly projects about the digestive system. Each idea is explained simply: the objective, the materials, step-by-step procedure, what to observe, and what students will learn.
These projects are suitable for a range of ages (primary to middle school). Many use safe, everyday materials and can be done in groups. Teachers can use them for science fairs, class demonstrations, or practical assignments.
Parents can try them at home to help children understand digestion using experiments and models. Read the safety tips below before starting, and then pick the projects that fit your grade level and available materials.
How to use this article
- Read the introduction and safety notes first.
- Choose projects that match your age and supervision level. Younger students should work with adult help.
- For each project, follow the materials and procedure carefully. Take notes and pictures for your report.
- At the end of each project, write a short conclusion saying what you learned and what surprised you.
Safety and materials note
- Many projects use food items, plastic bottles, balloons, water, vinegar, and simple household supplies. These are safe, but follow basic safety: wear gloves if needed, avoid eating experiment setups, and clean up spills promptly.
- For projects that use small parts or generate heat, adult supervision is required.
- If you have allergies (e.g., to eggs, wheat, or dairy), substitute materials as needed.
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30 Digestive System Project Ideas for Kids
1. Build a Digestive Tract Model with Tubes and Balloons
Age: 8–14
Objective: Show how food moves through the digestive tract and how organs help digestion.
Materials: Clear plastic tubing (or plastic wrap-wrapped rope), balloons, funnel, markers, tape, cardboard.
Procedure: Connect tubing to represent the esophagus, stomach (balloon), small intestine (long tubing), and large intestine (wider tubing). Use a funnel to pour soft food (mashed banana mixed with water) through the model and squeeze the “stomach” balloon to show churning.
What to observe: Movement of food through tubes, how squeezing mimics stomach muscles.
Learning: Mechanical digestion, peristalsis, organ positions, and function.
Tips: Label organs on cardboard. Use different colored food mixtures to show enzyme action later.
2. Enzyme in Action — Apple Turnover Test
Age: 9–15
Objective: Demonstrate how enzymes (like amylase) start breaking down food.
Materials: Fresh apple slices, saliva (or amylase solution if available), water, lemon juice, plates, timer.
Procedure: Put one apple slice in saliva or amylase solution and another in plain water and a third in lemon juice. Leave them for 30–60 minutes.
What to observe: The slice in saliva may soften or change color faster than in water because enzymes begin starch breakdown. Lemon juice (acid) will slow enzyme action.
Learning: Role of saliva and enzymes; how pH affects enzyme activity.
Tips: Discuss how chewing starts digestion.
3. Balloon Stomach — Show Churning and Acid Action
Age: 7–13
Objective: Model stomach churning and test the effect of acid on food.
Materials: Balloon, clear jar, vinegar, baking soda, crackers, water.
Procedure: Put crushed crackers and a little water into a balloon, tie it, and place it in a jar. Add vinegar to jar to show acid presence around it, and gently squeeze the balloon to mimic churning. For chemical test, mix crackers with vinegar to observe breakdown.
What to observe: Physical mixing and softer cracker texture in acid.
Learning: Stomach mechanical and chemical digestion, role of hydrochloric acid.
Tips: Use photos to show change in texture.
4. Digestive Timeline Poster
Age: 6–12
Objective: Create a visual timeline showing how long different foods stay in the digestive system.
Materials: Poster paper, markers, stickers, printed facts.
Procedure: Research approximate digestion times for fruits, proteins, fats, and grains. Draw a timeline from 0–72 hours and place foods at expected points.
What to observe: Different foods take different times to digest.
Learning: Differences in digestion speed for food types.
Tips: Use library or trusted websites for accurate times (teacher-led).
5. Make a Working Tooth Model
Age: 6–12
Objective: Show types of teeth and how they help digestion by breaking down food.
Materials: Clay or playdough, tooth-shape cutouts, paper, cardboard, small crackers.
Procedure: Create models of incisors, canines, premolars, and molars. Demonstrate chewing by breaking crackers using different “teeth” and explain their functions.
What to observe: How teeth shapes affect cutting vs grinding.
Learning: Mechanical digestion starts in the mouth; teeth specializations.
Tips: Include floss and toothbrush in display to discuss oral hygiene.
6. pH and Stomach Acid Test
Age: 10–15
Objective: Test pH changes when food mixes with stomach-like acid.
Materials: pH strips, vinegar or diluted hydrochloric acid mimic, food samples (milk, bread, apple), clear cups.
Procedure: Measure pH of food alone, then mix with vinegar and test pH again.
What to observe: Acidic environment lowers pH; some foods buffer acid.
Learning: pH role in digestion and enzyme activity.
Tips: Use safe acid substitutes like vinegar; compare results.
7. Simulate Absorption with a Sponge Intestine
Age: 8–14
Objective: Demonstrate how the small intestine absorbs nutrients.
Materials: Sponges (cut into long strips), water mixed with colored dye or sugar solution, measuring cups.
Procedure: Pour colored water through the sponge and collect the liquid that passes through. Squeeze the sponge to show absorption and release.
What to observe: Sponge holds water (like villi absorb nutrients) and releases it when squeezed.
Learning: Surface area and absorption; role of villi and microvilli.
Tips: Add more sponge surface area to show increased absorption.
8. Make a Model of Villi Using Felt or Paper
Age: 7–13
Objective: Show how villi increase surface area in the small intestine.
Materials: Felt, paper, scissors, glue, cardboard, ruler.
Procedure: Cut small finger-like pieces (villi) and glue onto a cardboard strip representing the intestine. Compare flat paper surface area to villi-covered area.
What to observe: More surface with villi equals more area to absorb nutrients.
Learning: Structure-function relationship in biology.
Tips: Use magnifying glass to view real images of villi for comparison.
9. Model of Peristalsis with a Glove or Hose
Age: 8–14
Objective: Show how muscles push food along the digestive tract.
Materials: Long glove or flexible hose, beads or small balls, clamps.
Procedure: Place beads inside glove/hose and squeeze sections in sequence to move beads forward.
What to observe: Wave-like motion propels contents — peristalsis.
Learning: Muscle contractions move food; coordinated movement is essential.
Tips: Time the beads to show speed differences with stronger squeezes.
10. Starch Test Using Iodine — Where Is Starch Broken Down?
Age: 10–15
Objective: Use iodine to test for starch presence before and after chewing.
Materials: Iodine solution, cooked potato or bread, water, droppers, plates.
Procedure: Put a small piece of bread in water and test with iodine (turns blue-black if starch present). Have a student chew a piece, then test saliva-mixed sample to see starch reduction.
What to observe: Chewed sample may show less starch color because saliva enzymes break starch into sugars.
Learning: Salivary amylase acts in the mouth; chemical digestion begins early.
Tips: Discuss limitations and control samples.
11. Make a Digestive System Board Game
Age: 9–14
Objective: Reinforce digestive system steps and organs through gameplay.
Materials: Cardboard, markers, dice, game pieces, question cards.
Procedure: Design a path that moves a “food” piece from mouth to anus. Add question spaces about organ functions, enzyme actions, and healthy habits.
What to observe: Students recall digestion sequence and functions while playing.
Learning: Reinforcement of facts; cooperative learning.
Tips: Include “bonus” squares for healthy foods and “penalty” squares for junk food.
12. Compare Digestion of Protein vs. Carbohydrate
Age: 11–15
Objective: Show how different enzymes act on different nutrients.
Materials: Gelatin (protein), bread (carbohydrate), vinegar (acid), saliva or enzyme solutions, small cups.
Procedure: Mix samples with saliva or enzyme. Observe texture changes after set time. Gelatin may not break down with amylase while bread does.
What to observe: Enzymes are specific to food types.
Learning: Enzyme specificity — proteases act on proteins, amylases on starches.
Tips: Discuss digestive tract regions where these enzymes work.
13. Make an Intestine Maze — Explore Mechanical Movement
Age: 6–12
Objective: Understand how food travels and faces resistance in the gut.
Materials: Cardboard, markers, small balls, tape.
Procedure: Build a winding maze (like intestines) and roll a ball (food) through. Add “obstacles” to model blockages or fiber slowing movement.
What to observe: How shape and obstacles affect travel time.
Learning: Role of intestine shape and peristalsis; importance of fiber.
Tips: Time runs with and without obstacles.
14. Make a Poop Composition Chart (Age-Appropriate)
Age: 9–14
Objective: Learn what waste contains and how hydration/diet affect stool.
Materials: Chart paper, markers, data from safe sources, sample images (teacher-provided).
Procedure: Research components of feces (water, bacteria, undigested food) and create a chart showing percentages. Discuss how hydration and fiber change results.
What to observe: Composition differences with diet.
Learning: Digestive waste and the importance of a balanced diet.
Tips: Keep discussion scientific and age-appropriate.
15. Make a Model Liver and Bile Action Demo
Age: 9–14
Objective: Show bile’s role in breaking fats into smaller droplets (emulsification).
Materials: Oil, water, dish soap (as bile mimic), two clear cups, egg yolk or milk.
Procedure: Mix oil and water in a cup (oil floats). Add a drop of dish soap and shake. Observe how soap helps break oil into tiny droplets. Compare with a control.
What to observe: Emulsification and increased mixing of fats into water.
Learning: Liver produces bile, which helps fat digestion in the small intestine.
Tips: Explain how bile is stored in the gallbladder.
16. Make a Simple Model of the Pancreas and Enzymes
Age: 10–15
Objective: Explain how the pancreas releases enzymes to digest fats, proteins, and carbs.
Materials: Labels, poster board, colored beads or small objects representing nutrient particles.
Procedure: Place beads in a mock “small intestine” area and show added pancreatic enzyme cards that turn large beads into smaller beads (representing breakdown).
What to observe: Enzymes help reduce nutrient size for absorption.
Learning: Pancreatic enzymes and their target nutrients.
Tips: Pair with the bile activity demo for a full fat digestion lesson.
17. Make an Acid-Base Balance Chart in the Gut
Age: 11–15
Objective: Show pH differences along the digestive tract from mouth to intestine.
Materials: pH paper, list of typical pH values for mouth, stomach, small intestine, large intestine (teacher-provided).
Procedure: Create a chart and have students predict where enzymes work best, then test with safe food mixtures and pH strips to compare.
What to observe: Stomach is very acidic; small intestine is more neutral to slightly alkaline.
Learning: pH affects enzyme function and intestinal environment.
Tips: Use accurate reference values from textbooks.
18. Create a “What Food Becomes” Flowchart
Age: 7–12
Objective: Trace one food item from bite to waste.
Materials: Flowchart paper, pictures of organs, arrows, glue.
Procedure: Choose a food (e.g., sandwich) and draw every step: chewing → saliva → stomach → small intestine → blood → cells → waste. Add short notes at each step.
What to observe: Complete path and changes at each stage.
Learning: Sequence of digestion and major changes.
Tips: Make it colorful and add short sentences.
19. Use a Blender to Model Mechanical Digestion (with Supervision)
Age: 10–15 (adult supervision)
Objective: Show how food is broken into smaller pieces.
Materials: Blender, bread, fruit, water, spoon, clear jar.
Procedure: Blend food with small amount of water to show physical breakdown. Compare blended food texture to chewed food.
What to observe: Size reduction mimics chewing and stomach churning.
Learning: Mechanical digestion increases surface area for enzymes.
Tips: Keep blender use safe and adult-supervised.
20. Bacterial Role — Fermentation Test (Safe, Controlled)
Age: 12–15 (with teacher oversight)
Objective: Show how gut bacteria ferment some foods.
Materials: Yogurt (as source of bacteria), sugar solutions, closed bottles, balloon.
Procedure: Mix sugar solution with a small amount of yogurt in a bottle, attach a balloon to the mouth, and leave in warm place. Gas produced will inflate the balloon showing fermentation.
What to observe: Gas production due to bacterial action.
Learning: Gut microbiome ferments fiber and produces gases and short-chain fatty acids.
Tips: Use small amounts and explain safety.
21. Create a Food Label Investigation — What Helps Digestion?
Age: 9–14
Objective: Read food labels to find fiber, sugar, and fat content and link to digestion.
Materials: Food labels, worksheets, calculator.
Procedure: Compare labels of cereals, snacks, and fruits. Rank them by fiber and sugar. Discuss which would be healthier for digestion.
What to observe: High fiber foods support digestion; high sugar may speed but not nourish.
Learning: Nutrition literacy and how food choices affect digestion.
Tips: Turn into a class survey and graph results.
22. Make a “Digestive Enzyme Relay” Classroom Game
Age: 7–12
Objective: Reinforce which enzyme acts where using a relay race format.
Materials: Cards labeled with enzymes (amylase, protease, lipase), organ stations, props.
Procedure: Students run to the correct organ station when given a food or enzyme card, explaining why the enzyme belongs there.
What to observe: Students recall enzyme–substrate relationships.
Learning: Active learning of biochemical roles.
Tips: Use small prizes or points for correct answers.
23. Observe Fiber’s Effect on Transit Time with a Simple Model
Age: 9–14
Objective: Show how fiber affects movement through the intestines.
Materials: Two hoses or tubes, mashed banana (low fiber) and mashed apple with added fiber (peel or bran), water, stopwatch.
Procedure: Push mixtures through tubes at same pressure and time the flow.
What to observe: Fiber mixture may flow differently, showing how fiber changes consistency and speed.
Learning: Dietary fiber’s role in stool bulk and transit time.
Tips: Discuss soluble vs. insoluble fiber.
24. Build a 3D Stomach with Paper Mâché and Show Acid Effects
Age: 8–14
Objective: Create a realistic model of the stomach and demonstrate internal acid presence.
Materials: Balloon core, paper mâché supplies, paint, vinegar, baking soda, small food pieces.
Procedure: Construct a stomach shell and inside place small food bits. Add a safe acidic mixture to show how food softens over time (do not seal if gas forms).
What to observe: Visual of stomach shape and internal action.
Learning: Stomach anatomy and chemical digestion.
Tips: Label parts like fundus, body, and pylorus.
25. Simulate Nutrient Transport into Bloodstream with Food Coloring
Age: 9–14
Objective: Model how nutrients move from intestine into blood.
Materials: Semi-permeable membrane (dialysis tubing), colored water, clear cups.
Procedure: Place colored solution inside dialysis tubing and place tubing in clean water. Over time, color diffuses through the tubing into water showing absorption.
What to observe: Diffusion as a model for nutrient transport.
Learning: Difference between diffusion and active transport; selectivity of membranes.
Tips: Discuss which nutrients need transporters vs simple diffusion.
26. Make a “Healthy Gut” Poster with Do’s and Don’ts
Age: 7–12
Objective: Teach habits that support healthy digestion.
Materials: Poster board, markers, cutouts of healthy foods, research facts.
Procedure: Students place foods and habits under “Do” (fiber, water, exercise) and “Don’t” (excess sugar, little water, no exercise). Add short explanations.
What to observe: Visual reminders of healthy choices.
Learning: Lifestyle effects on digestive health.
Tips: Add daily habits checklist.
27. Demonstrate the Role of Water in Digestion
Age: 6–12
Objective: Show how water helps dissolve food and move it through the system.
Materials: Two clear jars with mashed food; add water to one, leave the other drier.
Procedure: Stir both and notice ease of movement and texture differences. Time how fast each passes through a sieve.
What to observe: Higher water content makes movement easier and resembles healthy stool.
Learning: Hydration importance for digestion and elimination.
Tips: Link to everyday advice: drink water with meals.
28. Make a “Digestive Diary” — Track a Meal Through Your Body
Age: 10–15
Objective: Practice observation and record-keeping by tracking how a chosen meal is processed.
Materials: Notebook, pen, timer, simple food.
Procedure: Choose one meal and record times and sensations: chewing time, how long until stomach feels empty, next bowel movement timing (age-appropriate and optional). Note feelings, energy, and any digestion issues.
What to observe: Individual variation in digestion times and effects of food choices.
Learning: Personal awareness of digestion and healthy habits.
Tips: Emphasize privacy and optional nature for sensitive parts.
29. Build a Cross-Section Model of the Intestine with Clay
Age: 8–14
Objective: Show intestinal layers: mucosa, submucosa, muscle, serosa.
Materials: Modeling clay of different colors, plastic knives, labels.
Procedure: Roll clay layers into a tube and cut cross-sections to display layers. Label each and explain functions.
What to observe: Layered structure and role of muscle in peristalsis and mucosa in absorption.
Learning: Basic histology and structure-function relationships.
Tips: Use a magnified image to compare real tissue.
30. Prepare a Short Presentation: “Journey of a Sandwich”
Age: 7–15
Objective: Summarize digestion process in a class presentation.
Materials: Slides or poster, images, short script.
Procedure: Each student or group picks one sandwich and explains each step from mouth to cells, including enzymes and organs involved. Use diagrams from previous projects.
What to observe: Ability to explain digestion clearly and confidently.
Learning: Communication skills and conceptual mastery.
Tips: Include assessment questions for peers.
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Conclusion
These 30 projects cover many aspects of the digestive system: mechanical and chemical digestion, enzyme action, absorption, the role of accessory organs (liver, pancreas, gallbladder), the gut microbiome, and healthy habits that support digestion.
Choose projects that match your age and the time you have.
For science fair entries, combine two or more small projects (for example, enzyme tests plus a model of villi) to create a stronger display.
